diff --git a/src/libcalamares/utils/RAII.h b/src/libcalamares/utils/RAII.h
index 1cbead4a2..f3adb90f6 100644
--- a/src/libcalamares/utils/RAII.h
+++ b/src/libcalamares/utils/RAII.h
@@ -14,6 +14,7 @@
 #include <QObject>
 #include <QSignalBlocker>
 
+#include <optional>
 #include <type_traits>
 
 /** @brief Convenience to zero out and deleteLater of any QObject-derived-class
@@ -58,4 +59,20 @@ struct cBoolSetter
 /// @brief Blocks signals on a QObject until destruction
 using cSignalBlocker = QSignalBlocker;
 
+/** @brief Writes a value on destruction to a pointed-to location.
+ *
+ * If the pointer is non-null, write the last-given-value if there
+ * is one to the pointed-to object.
+ */
+template < typename T >
+struct cPointerSetter
+{
+    std::optional< T > m_value;
+    T* m_pointer;
+
+    cPointerSetter( T* p ) : m_pointer(p) {}
+    ~cPointerSetter() { if ( m_pointer && m_value.has_value() ) { *m_pointer = m_value.value(); } }
+
+    const T& operator=(const T& v) { m_value = v; return v; }
+};
 #endif
diff --git a/src/libcalamares/utils/Tests.cpp b/src/libcalamares/utils/Tests.cpp
index cdb37f20d..a689505e9 100644
--- a/src/libcalamares/utils/Tests.cpp
+++ b/src/libcalamares/utils/Tests.cpp
@@ -46,25 +46,27 @@ private Q_SLOTS:
 
     void testCommands();
 
-    /** @brief Test that all the UMask objects work correctly. */
+    /** @section Test that all the UMask objects work correctly. */
     void testUmask();
 
-    /** @brief Tests the entropy functions. */
+    /** @section Tests the entropy functions. */
     void testEntropy();
     void testPrintableEntropy();
     void testOddSizedPrintable();
 
-    /** @brief Tests the RAII bits. */
+    /** @section Tests the RAII bits. */
     void testBoolSetter();
+    void testPointerSetter();
 
-    /** @brief Tests the Traits bits. */
+    /** @section Tests the Traits bits. */
     void testTraits();
 
+    /** @section Testing the variants-methods */
     void testVariantStringListCode();
     void testVariantStringListYAMLDashed();
     void testVariantStringListYAMLBracketed();
 
-    /** @brief Test smart string truncation. */
+    /** @section Test smart string truncation. */
     void testStringTruncation();
     void testStringTruncationShorter();
     void testStringTruncationDegenerate();
@@ -360,6 +362,50 @@ LibCalamaresTests::testBoolSetter()
     QVERIFY( b );
 }
 
+void
+LibCalamaresTests::testPointerSetter()
+{
+    int special = 17;
+
+    QCOMPARE( special, 17 );
+    {
+        cPointerSetter p( &special );
+    }
+    QCOMPARE( special, 17 );
+    {
+        cPointerSetter p( &special );
+        p = 18;
+    }
+    QCOMPARE( special, 18 );
+    {
+        cPointerSetter p( &special );
+        p = 20;
+        p = 3;
+    }
+    QCOMPARE( special, 3 );
+    {
+        cPointerSetter<int> p( nullptr );
+    }
+    QCOMPARE( special, 3 );
+    {
+        // "don't do this" .. order of destructors is important
+        cPointerSetter p( &special );
+        cPointerSetter q( &special );
+        p = 17;
+    }
+    QCOMPARE( special, 17 );
+    {
+        // "don't do this" .. order of destructors is important
+        cPointerSetter p( &special );
+        cPointerSetter q( &special );
+        p = 34;
+        q = 2;
+        // q destroyed first, then p
+    }
+    QCOMPARE( special, 34 );
+}
+
+
 /* Demonstration of Traits support for has-a-method or not.
  *
  * We have two classes, c1 and c2; one has a method do_the_thing() and the
@@ -431,17 +477,31 @@ LibCalamaresTests::testVariantStringListCode()
         QCOMPARE( getStringList( m, key ), QStringList {} );
         m.insert( key, 17 );
         QCOMPARE( getStringList( m, key ), QStringList {} );
-        m.insert( key, QString( "more strings" ) );
-        QCOMPARE( getStringList( m, key ),
-                  QStringList { "more strings" } );  // A single string **can** be considered a stringlist!
         m.insert( key, QVariant {} );
         QCOMPARE( getStringList( m, key ), QStringList {} );
     }
 
     {
-        // Things that are stringlists
+        // Things that are **like** stringlists
+        QVariantMap m;
+        m.insert( key, QString( "astring" ) );
+        QCOMPARE( getStringList( m, key ).count(), 1 );
+        QCOMPARE( getStringList( m, key ),
+                  QStringList { "astring" } );  // A single string **can** be considered a stringlist!
+        m.insert( key, QString( "more strings" ) );
+        QCOMPARE( getStringList( m, key ).count(), 1 );
+        QCOMPARE( getStringList( m, key ),
+                  QStringList { "more strings" } );
+        m.insert( key, QString() );
+        QCOMPARE( getStringList( m, key ).count(), 1 );
+        QCOMPARE( getStringList( m, key ), QStringList { QString() } );
+    }
+
+    {
+        // Things that are definitely stringlists
         QVariantMap m;
         m.insert( key, QStringList { "aap", "noot" } );
+        QCOMPARE( getStringList( m, key ).count(), 2 );
         QVERIFY( getStringList( m, key ).contains( "aap" ) );
         QVERIFY( !getStringList( m, key ).contains( "mies" ) );
     }
diff --git a/src/libcalamares/utils/Variant.h b/src/libcalamares/utils/Variant.h
index e1261f877..ab9e73f90 100644
--- a/src/libcalamares/utils/Variant.h
+++ b/src/libcalamares/utils/Variant.h
@@ -25,13 +25,17 @@ namespace CalamaresUtils
  */
 DLLEXPORT bool getBool( const QVariantMap& map, const QString& key, bool d = false );
 
-/**
- * Get a string value from a mapping with a given key; returns @p d if no value.
+/** @brief Get a string value from a mapping with a given key; returns @p d if no value.
+ *
+ * The value must be an actual string; numbers are not automatically converted to strings,
+ * nor are lists flattened or converted.
  */
 DLLEXPORT QString getString( const QVariantMap& map, const QString& key, const QString& d = QString() );
 
-/**
- * Get a string list from a mapping with a given key; returns @p d if no value.
+/** @brief Get a string list from a mapping with a given key; returns @p d if no value.
+ *
+ * This is slightly more lenient that getString(), and a single-string value will
+ * be returned as a 1-item list.
  */
 DLLEXPORT QStringList getStringList( const QVariantMap& map, const QString& key, const QStringList& d = QStringList() );
 
diff --git a/src/modules/packagechooser/Config.h b/src/modules/packagechooser/Config.h
index 4cb545cb8..5959e3ea4 100644
--- a/src/modules/packagechooser/Config.h
+++ b/src/modules/packagechooser/Config.h
@@ -72,7 +72,7 @@ public:
      */
     void updateGlobalStorage( const QStringList& selected ) const;
     /// As updateGlobalStorage() with an empty selection list
-    void updateGlobalStorage() const { updateGlobalStorage( QStringList() ); }
+    void fillGSSecondaryConfiguration() const { updateGlobalStorage( QStringList() ); }
 
 private:
     PackageListModel* m_model = nullptr;
diff --git a/src/modules/partition/CMakeLists.txt b/src/modules/partition/CMakeLists.txt
index bffb2128c..26d4ffae7 100644
--- a/src/modules/partition/CMakeLists.txt
+++ b/src/modules/partition/CMakeLists.txt
@@ -49,9 +49,11 @@ if ( KPMcore_FOUND AND Qt5DBus_FOUND AND KF5CoreAddons_FOUND AND KF5Config_FOUND
         TYPE viewmodule
         EXPORT_MACRO PLUGINDLLEXPORT_PRO
         SOURCES
+            Config.cpp
+            PartitionViewStep.cpp
+
             core/BootLoaderModel.cpp
             core/ColorUtils.cpp
-            core/Config.cpp
             core/DeviceList.cpp
             core/DeviceModel.cpp
             core/KPMHelpers.cpp
@@ -75,7 +77,6 @@ if ( KPMcore_FOUND AND Qt5DBus_FOUND AND KF5CoreAddons_FOUND AND KF5Config_FOUND
             gui/PartitionLabelsView.cpp
             gui/PartitionSizeController.cpp
             gui/PartitionSplitterWidget.cpp
-            gui/PartitionViewStep.cpp
             gui/ResizeVolumeGroupDialog.cpp
             gui/ScanningDialog.cpp
             gui/ReplaceWidget.cpp
diff --git a/src/modules/partition/core/Config.cpp b/src/modules/partition/Config.cpp
similarity index 67%
rename from src/modules/partition/core/Config.cpp
rename to src/modules/partition/Config.cpp
index 0afcee83d..82c0ad846 100644
--- a/src/modules/partition/core/Config.cpp
+++ b/src/modules/partition/Config.cpp
@@ -9,6 +9,8 @@
 
 #include "Config.h"
 
+#include "core/PartUtils.h"
+
 #include "GlobalStorage.h"
 #include "JobQueue.h"
 #include "utils/Logger.h"
@@ -180,7 +182,7 @@ Config::setInstallChoice( InstallChoice c )
     if ( c != m_installChoice )
     {
         m_installChoice = c;
-        emit installChoiceChanged( c );
+        Q_EMIT installChoiceChanged( c );
         ::updateGlobalStorage( c, m_swapChoice );
     }
 }
@@ -202,16 +204,98 @@ Config::setSwapChoice( Config::SwapChoice c )
     if ( c != m_swapChoice )
     {
         m_swapChoice = c;
-        emit swapChoiceChanged( c );
+        Q_EMIT swapChoiceChanged( c );
         ::updateGlobalStorage( m_installChoice, c );
     }
 }
 
-bool
-Config::allowManualPartitioning() const
+void
+Config::setEraseFsTypeChoice( const QString& choice )
+{
+    QString canonicalChoice = PartUtils::canonicalFilesystemName( choice, nullptr );
+    if ( canonicalChoice != m_eraseFsTypeChoice )
+    {
+        m_eraseFsTypeChoice = canonicalChoice;
+        Q_EMIT eraseModeFilesystemChanged( canonicalChoice );
+    }
+}
+
+static void
+fillGSConfigurationEFI( Calamares::GlobalStorage* gs, const QVariantMap& configurationMap )
+{
+    // Set up firmwareType global storage entry. This is used, e.g. by the bootloader module.
+    QString firmwareType( PartUtils::isEfiSystem() ? QStringLiteral( "efi" ) : QStringLiteral( "bios" ) );
+    gs->insert( "firmwareType", firmwareType );
+
+    gs->insert( "efiSystemPartition", CalamaresUtils::getString( configurationMap, "efiSystemPartition", QStringLiteral( "/boot/efi" ) ) );
+
+    // Read and parse key efiSystemPartitionSize
+    if ( configurationMap.contains( "efiSystemPartitionSize" ) )
+    {
+        gs->insert( "efiSystemPartitionSize", CalamaresUtils::getString( configurationMap, "efiSystemPartitionSize" ) );
+    }
+
+    // Read and parse key efiSystemPartitionName
+    if ( configurationMap.contains( "efiSystemPartitionName" ) )
+    {
+        gs->insert( "efiSystemPartitionName", CalamaresUtils::getString( configurationMap, "efiSystemPartitionName" ) );
+    }
+}
+
+void
+Config::fillConfigurationFSTypes(const QVariantMap& configurationMap)
 {
     Calamares::GlobalStorage* gs = Calamares::JobQueue::instance()->globalStorage();
-    return gs->value( "allowManualPartitioning" ).toBool();
+
+
+    // The defaultFileSystemType setting needs a bit more processing,
+    // as we want to cover various cases (such as different cases)
+    QString fsName = CalamaresUtils::getString( configurationMap, "defaultFileSystemType" );
+    QString fsRealName;
+    FileSystem::Type fsType = FileSystem::Type::Unknown;
+    if ( fsName.isEmpty() )
+    {
+        cWarning() << "Partition-module setting *defaultFileSystemType* is missing, will use ext4";
+        fsRealName = PartUtils::canonicalFilesystemName( QStringLiteral("ext4"), &fsType );
+    }
+    else
+    {
+        fsRealName = PartUtils::canonicalFilesystemName( fsName, &fsType );
+        if ( fsType == FileSystem::Type::Unknown )
+        {
+            cWarning() << "Partition-module setting *defaultFileSystemType* is bad (" << fsName << ") using ext4 instead";
+            fsRealName = PartUtils::canonicalFilesystemName( QStringLiteral("ext4"), &fsType );
+        }
+        else if ( fsRealName != fsName )
+        {
+            cWarning() << "Partition-module setting *defaultFileSystemType* changed to" << fsRealName;
+        }
+    }
+    Q_ASSERT( fsType != FileSystem::Type::Unknown );
+    m_defaultFsType = fsType;
+    gs->insert( "defaultFileSystemType", fsRealName );
+
+    // TODO: canonicalize the names? How is translation supposed to work?
+    m_eraseFsTypes = CalamaresUtils::getStringList( configurationMap, "availableFileSystemTypes" );
+    if ( !m_eraseFsTypes.contains( fsRealName ) )
+    {
+        if ( !m_eraseFsTypes.isEmpty() )
+        {
+            // Explicitly set, and doesn't include the default
+            cWarning() << "Partition-module *availableFileSystemTypes* does not contain the default" << fsRealName;
+            m_eraseFsTypes.prepend( fsRealName );
+        }
+        else
+        {
+            // Not explicitly set, so it's empty; don't complain
+            m_eraseFsTypes = QStringList { fsRealName };
+        }
+    }
+
+    Q_ASSERT( !m_eraseFsTypes.isEmpty() );
+    Q_ASSERT( m_eraseFsTypes.contains( fsRealName ) );
+    m_eraseFsTypeChoice = fsRealName;
+    Q_EMIT eraseModeFilesystemChanged( m_eraseFsTypeChoice );
 }
 
 
@@ -236,27 +320,18 @@ Config::setConfigurationMap( const QVariantMap& configurationMap )
     }
     setSwapChoice( m_initialSwapChoice );
 
-    Calamares::GlobalStorage* gs = Calamares::JobQueue::instance()->globalStorage();
-    gs->insert( "allowManualPartitioning",
-                CalamaresUtils::getBool( configurationMap, "allowManualPartitioning", true ) );
+    m_allowManualPartitioning = CalamaresUtils::getBool( configurationMap, "allowManualPartitioning", true );
 
-    if ( configurationMap.contains( "requiredPartitionTableType" )
-         && configurationMap.value( "requiredPartitionTableType" ).type() == QVariant::List )
-    {
-        m_requiredPartitionTableType.clear();
-        m_requiredPartitionTableType.append( configurationMap.value( "requiredPartitionTableType" ).toStringList() );
-    }
-    else if ( configurationMap.contains( "requiredPartitionTableType" )
-              && configurationMap.value( "requiredPartitionTableType" ).type() == QVariant::String )
-    {
-        m_requiredPartitionTableType.clear();
-        m_requiredPartitionTableType.append( configurationMap.value( "requiredPartitionTableType" ).toString() );
-    }
+    Calamares::GlobalStorage* gs = Calamares::JobQueue::instance()->globalStorage();
+    m_requiredPartitionTableType = CalamaresUtils::getStringList( configurationMap, "requiredPartitionTableType" );
     gs->insert( "requiredPartitionTableType", m_requiredPartitionTableType );
+
+    fillGSConfigurationEFI(gs, configurationMap);
+    fillConfigurationFSTypes( configurationMap );
 }
 
 void
-Config::updateGlobalStorage() const
+Config::fillGSSecondaryConfiguration() const
 {
     // If there's no setting (e.g. from the welcome page) for required storage
     // then use ours, if it was set.
diff --git a/src/modules/partition/core/Config.h b/src/modules/partition/Config.h
similarity index 70%
rename from src/modules/partition/core/Config.h
rename to src/modules/partition/Config.h
index 57230b6e8..3365403fa 100644
--- a/src/modules/partition/core/Config.h
+++ b/src/modules/partition/Config.h
@@ -12,6 +12,8 @@
 
 #include "utils/NamedEnum.h"
 
+#include <kpmcore/fs/filesystem.h>
+
 #include <QObject>
 #include <QSet>
 
@@ -24,6 +26,9 @@ class Config : public QObject
     ///@brief The swap choice (None, Small, Hibernate, ...) which only makes sense when Erase is chosen
     Q_PROPERTY( SwapChoice swapChoice READ swapChoice WRITE setSwapChoice NOTIFY swapChoiceChanged )
 
+    ///@brief Name of the FS that will be used when erasing type disk (e.g. "default filesystem")
+    Q_PROPERTY( QString eraseModeFilesystem READ eraseFsType WRITE setEraseFsTypeChoice NOTIFY eraseModeFilesystemChanged )
+
     Q_PROPERTY( bool allowManualPartitioning READ allowManualPartitioning CONSTANT FINAL )
 
 public:
@@ -54,8 +59,19 @@ public:
     static const NamedEnumTable< SwapChoice >& swapChoiceNames();
     using SwapChoiceSet = QSet< SwapChoice >;
 
+    using EraseFsTypesSet = QStringList;
+
     void setConfigurationMap( const QVariantMap& );
-    void updateGlobalStorage() const;
+    /** @brief Set GS values where other modules configuration has priority
+     *
+     * Some "required" values are duplicated between modules; if some
+     * othe module hasn't already set the GS value, take a value from
+     * the partitioning configuration.
+     *
+     * Applicable GS keys:
+     *  - requiredStorageGiB
+     */
+    void fillGSSecondaryConfiguration() const;
 
     /** @brief What kind of installation (partitioning) is requested **initially**?
      *
@@ -94,20 +110,44 @@ public:
      */
     SwapChoice swapChoice() const { return m_swapChoice; }
 
-    ///@brief Is manual partitioning allowed (not explicitly disnabled in the config file)?
-    bool allowManualPartitioning() const;
+    /** @brief Get the list of configured FS types to use with *erase* mode
+     *
+     * This list is not empty.
+     */
+    EraseFsTypesSet eraseFsTypes() const { return m_eraseFsTypes; }
+
+    /** @brief Currently-selected FS type for *erase* mode
+     */
+    QString eraseFsType() const { return m_eraseFsTypeChoice; }
+
+    /** @brief Configured default FS type (for other modes than erase)
+     *
+     * This is not "Unknown" or "Unformatted"
+     */
+    FileSystem::Type defaultFsType() const { return m_defaultFsType; }
+
+    ///@brief Is manual partitioning allowed (not explicitly disabled in the config file)?
+    bool allowManualPartitioning() const { return m_allowManualPartitioning; }
 
 public Q_SLOTS:
     void setInstallChoice( int );  ///< Translates a button ID or so to InstallChoice
     void setInstallChoice( InstallChoice );
     void setSwapChoice( int );  ///< Translates a button ID or so to SwapChoice
     void setSwapChoice( SwapChoice );
+    void setEraseFsTypeChoice( const QString& filesystemName ); ///< See property eraseModeFilesystem
 
 Q_SIGNALS:
     void installChoiceChanged( InstallChoice );
     void swapChoiceChanged( SwapChoice );
+    void eraseModeFilesystemChanged( const QString& );
 
 private:
+    /** @brief Handle FS-type configuration, for erase and default */
+    void fillConfigurationFSTypes( const QVariantMap& configurationMap );
+    EraseFsTypesSet m_eraseFsTypes;
+    QString m_eraseFsTypeChoice;
+    FileSystem::Type m_defaultFsType;
+
     SwapChoiceSet m_swapChoices;
     SwapChoice m_initialSwapChoice = NoSwap;
     SwapChoice m_swapChoice = NoSwap;
@@ -115,6 +155,8 @@ private:
     InstallChoice m_installChoice = NoChoice;
     qreal m_requiredStorageGiB = 0.0;  // May duplicate setting in the welcome module
     QStringList m_requiredPartitionTableType;
+
+    bool m_allowManualPartitioning = true;
 };
 
 /** @brief Given a set of swap choices, return a sensible value from it.
diff --git a/src/modules/partition/gui/PartitionViewStep.cpp b/src/modules/partition/PartitionViewStep.cpp
similarity index 91%
rename from src/modules/partition/gui/PartitionViewStep.cpp
rename to src/modules/partition/PartitionViewStep.cpp
index bbb865f30..fc6b3e50c 100644
--- a/src/modules/partition/gui/PartitionViewStep.cpp
+++ b/src/modules/partition/PartitionViewStep.cpp
@@ -11,10 +11,10 @@
  *
  */
 
-#include "gui/PartitionViewStep.h"
+#include "PartitionViewStep.h"
 
+#include "Config.h"
 #include "core/BootLoaderModel.h"
-#include "core/Config.h"
 #include "core/DeviceModel.h"
 #include "core/PartitionCoreModule.h"
 #include "gui/ChoicePage.h"
@@ -327,7 +327,7 @@ PartitionViewStep::isNextEnabled() const
 void
 PartitionViewStep::nextPossiblyChanged( bool )
 {
-    emit nextStatusChanged( isNextEnabled() );
+    Q_EMIT nextStatusChanged( isNextEnabled() );
 }
 
 bool
@@ -368,7 +368,7 @@ PartitionViewStep::isAtEnd() const
 void
 PartitionViewStep::onActivate()
 {
-    m_config->updateGlobalStorage();
+    m_config->fillGSSecondaryConfiguration();
 
     // if we're coming back to PVS from the next VS
     if ( m_widget->currentWidget() == m_choicePage && m_config->installChoice() == Config::InstallChoice::Alongside )
@@ -541,32 +541,11 @@ PartitionViewStep::onLeave()
 void
 PartitionViewStep::setConfigurationMap( const QVariantMap& configurationMap )
 {
-    Logger::Once o;
-
     m_config->setConfigurationMap( configurationMap );
 
     // Copy the efiSystemPartition setting to the global storage. It is needed not only in
     // the EraseDiskPage, but also in the bootloader configuration modules (grub, bootloader).
     Calamares::GlobalStorage* gs = Calamares::JobQueue::instance()->globalStorage();
-    QString efiSP = CalamaresUtils::getString( configurationMap, "efiSystemPartition", QStringLiteral( "/boot/efi" ) );
-    gs->insert( "efiSystemPartition", efiSP );
-
-    // Set up firmwareType global storage entry. This is used, e.g. by the bootloader module.
-    QString firmwareType( PartUtils::isEfiSystem() ? QStringLiteral( "efi" ) : QStringLiteral( "bios" ) );
-    cDebug() << o << "Setting firmwareType to" << firmwareType;
-    gs->insert( "firmwareType", firmwareType );
-
-    // Read and parse key efiSystemPartitionSize
-    if ( configurationMap.contains( "efiSystemPartitionSize" ) )
-    {
-        gs->insert( "efiSystemPartitionSize", CalamaresUtils::getString( configurationMap, "efiSystemPartitionSize" ) );
-    }
-
-    // Read and parse key efiSystemPartitionName
-    if ( configurationMap.contains( "efiSystemPartitionName" ) )
-    {
-        gs->insert( "efiSystemPartitionName", CalamaresUtils::getString( configurationMap, "efiSystemPartitionName" ) );
-    }
 
     // Read and parse key swapPartitionName
     if ( configurationMap.contains( "swapPartitionName" ) )
@@ -582,30 +561,6 @@ PartitionViewStep::setConfigurationMap( const QVariantMap& configurationMap )
     gs->insert( "enableLuksAutomatedPartitioning",
                 CalamaresUtils::getBool( configurationMap, "enableLuksAutomatedPartitioning", true ) );
 
-    // The defaultFileSystemType setting needs a bit more processing,
-    // as we want to cover various cases (such as different cases)
-    QString fsName = CalamaresUtils::getString( configurationMap, "defaultFileSystemType" );
-    FileSystem::Type fsType;
-    if ( fsName.isEmpty() )
-    {
-        cWarning() << "Partition-module setting *defaultFileSystemType* is missing, will use ext4";
-    }
-    QString fsRealName = PartUtils::findFS( fsName, &fsType );
-    if ( fsRealName == fsName )
-    {
-        cDebug() << o << "Partition-module setting *defaultFileSystemType*" << fsRealName;
-    }
-    else if ( fsType != FileSystem::Unknown )
-    {
-        cWarning() << "Partition-module setting *defaultFileSystemType* changed" << fsRealName;
-    }
-    else
-    {
-        cWarning() << "Partition-module setting *defaultFileSystemType* is bad (" << fsName << ") using" << fsRealName
-                   << "instead.";
-    }
-    gs->insert( "defaultFileSystemType", fsRealName );
-
     QString partitionTableName = CalamaresUtils::getString( configurationMap, "defaultPartitionTableType" );
     if ( partitionTableName.isEmpty() )
     {
@@ -627,7 +582,7 @@ PartitionViewStep::setConfigurationMap( const QVariantMap& configurationMap )
     QFuture< void > future = QtConcurrent::run( this, &PartitionViewStep::initPartitionCoreModule );
     m_future->setFuture( future );
 
-    m_core->initLayout( fsType == FileSystem::Unknown ? FileSystem::Ext4 : fsType,
+    m_core->initLayout( m_config->defaultFsType(),
                         configurationMap.value( "partitionLayout" ).toList() );
 }
 
diff --git a/src/modules/partition/gui/PartitionViewStep.h b/src/modules/partition/PartitionViewStep.h
similarity index 100%
rename from src/modules/partition/gui/PartitionViewStep.h
rename to src/modules/partition/PartitionViewStep.h
diff --git a/src/modules/partition/core/DeviceModel.cpp b/src/modules/partition/core/DeviceModel.cpp
index 46a181b33..33aae20c0 100644
--- a/src/modules/partition/core/DeviceModel.cpp
+++ b/src/modules/partition/core/DeviceModel.cpp
@@ -132,7 +132,7 @@ DeviceModel::swapDevice( Device* oldDevice, Device* newDevice )
 
     m_devices[ indexOfOldDevice ] = newDevice;
 
-    emit dataChanged( index( indexOfOldDevice ), index( indexOfOldDevice ) );
+    Q_EMIT dataChanged( index( indexOfOldDevice ), index( indexOfOldDevice ) );
 }
 
 void
diff --git a/src/modules/partition/core/PartUtils.cpp b/src/modules/partition/core/PartUtils.cpp
index 47654a2be..2f269d37f 100644
--- a/src/modules/partition/core/PartUtils.cpp
+++ b/src/modules/partition/core/PartUtils.cpp
@@ -22,6 +22,7 @@
 #include "partition/PartitionQuery.h"
 #include "utils/CalamaresUtilsSystem.h"
 #include "utils/Logger.h"
+#include "utils/RAII.h"
 
 #include <kpmcore/backend/corebackend.h>
 #include <kpmcore/backend/corebackendmanager.h>
@@ -479,21 +480,19 @@ isEfiBootable( const Partition* candidate )
 }
 
 QString
-findFS( QString fsName, FileSystem::Type* fsType )
+canonicalFilesystemName( const QString& fsName, FileSystem::Type* fsType )
 {
-    QStringList fsLanguage { QLatin1String( "C" ) };  // Required language list to turn off localization
+    cPointerSetter type( fsType );
     if ( fsName.isEmpty() )
     {
-        fsName = QStringLiteral( "ext4" );
+        type = FileSystem::Ext4;
+        return QStringLiteral( "ext4" );
     }
 
-    FileSystem::Type tmpType = FileSystem::typeForName( fsName, fsLanguage );
-    if ( tmpType != FileSystem::Unknown )
+    QStringList fsLanguage { QLatin1String( "C" ) };  // Required language list to turn off localization
+
+    if ( ( type = FileSystem::typeForName( fsName, fsLanguage ) ) != FileSystem::Unknown )
     {
-        if ( fsType )
-        {
-            *fsType = tmpType;
-        }
         return fsName;
     }
 
@@ -513,7 +512,6 @@ findFS( QString fsName, FileSystem::Type* fsType )
     }
 
     cWarning() << "Filesystem" << fsName << "not found, using ext4";
-    fsName = QStringLiteral( "ext4" );
     // fsType can be used to check whether fsName was a valid filesystem.
     if ( fsType )
     {
@@ -533,7 +531,8 @@ findFS( QString fsName, FileSystem::Type* fsType )
         }
     }
 #endif
-    return fsName;
+    type = FileSystem::Unknown;
+    return QStringLiteral( "ext4" );
 }
 
 }  // namespace PartUtils
diff --git a/src/modules/partition/core/PartUtils.h b/src/modules/partition/core/PartUtils.h
index 404dd5a77..5e84e379b 100644
--- a/src/modules/partition/core/PartUtils.h
+++ b/src/modules/partition/core/PartUtils.h
@@ -91,11 +91,13 @@ bool isEfiBootable( const Partition* candidate );
 /** @brief translate @p fsName into a recognized name and type
  *
  * Makes several attempts to translate the string into a
- * name that KPMCore will recognize.
+ * name that KPMCore will recognize. Returns the canonical
+ * filesystem name (e.g. asking for "EXT4" will return "ext4").
+ *
  * The corresponding filesystem type is stored in @p fsType, and
  * its value is FileSystem::Unknown if @p fsName is not recognized.
  */
-QString findFS( QString fsName, FileSystem::Type* fsType );
+QString canonicalFilesystemName( const QString& fsName, FileSystem::Type* fsType );
 
 }  // namespace PartUtils
 
diff --git a/src/modules/partition/core/PartitionActions.cpp b/src/modules/partition/core/PartitionActions.cpp
index 1a3f6246b..422c1d38f 100644
--- a/src/modules/partition/core/PartitionActions.cpp
+++ b/src/modules/partition/core/PartitionActions.cpp
@@ -16,13 +16,12 @@
 #include "core/PartitionCoreModule.h"
 #include "core/PartitionInfo.h"
 
-#include "utils/CalamaresUtilsSystem.h"
-#include "utils/NamedEnum.h"
-#include "utils/Units.h"
-
 #include "GlobalStorage.h"
 #include "JobQueue.h"
+#include "utils/CalamaresUtilsSystem.h"
 #include "utils/Logger.h"
+#include "utils/NamedEnum.h"
+#include "utils/Units.h"
 
 #include <kpmcore/core/device.h>
 #include <kpmcore/core/partition.h>
@@ -109,6 +108,12 @@ doAutopartition( PartitionCoreModule* core, Device* dev, Choices::AutoPartitionO
         partType = isEfi ? PartitionTable::gpt : PartitionTable::msdos;
     }
 
+    // Looking up the defaultFsType (which should name a filesystem type)
+    // will log an error and set the type to Unknown if there's something wrong.
+    FileSystem::Type type = FileSystem::Unknown;
+    PartUtils::canonicalFilesystemName( o.defaultFsType, &type );
+    core->initLayout( type == FileSystem::Unknown ? FileSystem::Ext4 : type );
+
     core->createPartitionTable( dev, partType );
 
     if ( isEfi )
diff --git a/src/modules/partition/core/PartitionActions.h b/src/modules/partition/core/PartitionActions.h
index 3a345dc4e..4a60f4735 100644
--- a/src/modules/partition/core/PartitionActions.h
+++ b/src/modules/partition/core/PartitionActions.h
@@ -10,7 +10,7 @@
 #ifndef PARTITIONACTIONS_H
 #define PARTITIONACTIONS_H
 
-#include "core/Config.h"
+#include "Config.h"
 
 #include <QSet>
 #include <QString>
diff --git a/src/modules/partition/core/PartitionCoreModule.cpp b/src/modules/partition/core/PartitionCoreModule.cpp
index 363d9daef..e2c91fbee 100644
--- a/src/modules/partition/core/PartitionCoreModule.cpp
+++ b/src/modules/partition/core/PartitionCoreModule.cpp
@@ -687,7 +687,7 @@ void
 PartitionCoreModule::refreshPartition( Device* device, Partition* )
 {
     // Keep it simple for now: reset the model. This can be improved to cause
-    // the model to emit dataChanged() for the affected row instead, avoiding
+    // the model to Q_EMIT dataChanged() for the affected row instead, avoiding
     // the loss of the current selection.
     auto model = partitionModelForDevice( device );
     Q_ASSERT( model );
@@ -966,7 +966,7 @@ PartitionCoreModule::revert()
     m_deviceInfos.clear();
     doInit();
     updateIsDirty();
-    emit reverted();
+    Q_EMIT reverted();
 }
 
 
@@ -1040,7 +1040,7 @@ PartitionCoreModule::revertDevice( Device* dev, bool individualRevert )
     {
         refreshAfterModelChange();
     }
-    emit deviceReverted( newDev );
+    Q_EMIT deviceReverted( newDev );
 }
 
 
diff --git a/src/modules/partition/core/PartitionLayout.cpp b/src/modules/partition/core/PartitionLayout.cpp
index 23eaeda62..a8ed206d8 100644
--- a/src/modules/partition/core/PartitionLayout.cpp
+++ b/src/modules/partition/core/PartitionLayout.cpp
@@ -75,7 +75,7 @@ PartitionLayout::PartitionEntry::PartitionEntry( const QString& label,
     , partMinSize( minSize )
     , partMaxSize( maxSize )
 {
-    PartUtils::findFS( fs, &partFileSystem );
+    PartUtils::canonicalFilesystemName( fs, &partFileSystem );
 }
 
 
@@ -95,7 +95,7 @@ PartitionLayout::addEntry( const PartitionEntry& entry )
 void
 PartitionLayout::init( FileSystem::Type defaultFsType, const QVariantList& config )
 {
-    bool ok;
+    bool ok = true;  // bogus argument to getSubMap()
 
     m_partLayout.clear();
 
@@ -130,10 +130,71 @@ PartitionLayout::init( FileSystem::Type defaultFsType, const QVariantList& confi
 
     if ( !m_partLayout.count() )
     {
-        addEntry( { defaultFsType, QString( "/" ), QString( "100%" ) } );
+        // Unknown will be translated to defaultFsType at apply-time
+        addEntry( { FileSystem::Type::Unknown, QString( "/" ), QString( "100%" ) } );
     }
+
+    setDefaultFsType( defaultFsType );
+}
+
+void
+PartitionLayout::setDefaultFsType(FileSystem::Type defaultFsType)
+{
+    using T = FileSystem::Type;
+    switch ( defaultFsType )
+    {
+        case T::Unknown:
+        case T::Unformatted:
+        case T::Extended:
+        case T::LinuxSwap:
+        case T::Luks:
+        case T::Ocfs2:
+        case T::Lvm2_PV:
+        case T::Udf:
+        case T::Iso9660:
+        case T::Luks2:
+        case T::LinuxRaidMember:
+        case T::BitLocker:
+            // bad bad
+            cWarning() << "The selected default FS" << defaultFsType << "is not suitable." << "Using ext4 instead.";
+            defaultFsType = T::Ext4;
+            break;
+        case T::Ext2:
+        case T::Ext3:
+        case T::Ext4:
+        case T::Fat32:
+        case T::Ntfs:
+        case T::Reiser4:
+        case T::ReiserFS:
+        case T::Xfs:
+        case T::Jfs:
+        case T::Btrfs:
+        case T::Exfat:
+        case T::F2fs:
+            // ok
+            break;
+        case T::Fat12:
+        case T::Fat16:
+        case T::Hfs:
+        case T::HfsPlus:
+        case T::Ufs:
+        case T::Hpfs:
+        case T::Zfs:
+        case T::Nilfs2:
+        case T::Apfs:
+        case T::Minix:
+            // weird
+            cWarning() << "The selected default FS" << defaultFsType << "is unusual, but not wrong.";
+            break;
+        default:
+            cWarning() << "The selected default FS" << defaultFsType << "is not known to Calamares." << "Using ext4 instead.";
+            defaultFsType = T::Ext4;
+    }
+
+    m_defaultFsType = defaultFsType;
 }
 
+
 QList< Partition* >
 PartitionLayout::createPartitions( Device* dev,
                                    qint64 firstSector,
@@ -142,6 +203,9 @@ PartitionLayout::createPartitions( Device* dev,
                                    PartitionNode* parent,
                                    const PartitionRole& role )
 {
+    // Make sure the default FS is sensible; warn and use ext4 if not
+    setDefaultFsType( m_defaultFsType );
+
     QList< Partition* > partList;
     // Map each partition entry to its requested size (0 when calculated later)
     QMap< const PartitionLayout::PartitionEntry*, qint64 > partSectorsMap;
@@ -210,6 +274,8 @@ PartitionLayout::createPartitions( Device* dev,
         }
     }
 
+    auto correctFS = [d=m_defaultFsType]( FileSystem::Type t ) { return t == FileSystem::Type::Unknown ? d : t; };
+
     // Create the partitions.
     currentSector = firstSector;
     availableSectors = totalSectors;
@@ -229,7 +295,7 @@ PartitionLayout::createPartitions( Device* dev,
             part = KPMHelpers::createNewPartition( parent,
                                                    *dev,
                                                    role,
-                                                   entry.partFileSystem,
+                                                   correctFS( entry.partFileSystem ),
                                                    entry.partLabel,
                                                    currentSector,
                                                    currentSector + sectors - 1,
@@ -240,7 +306,7 @@ PartitionLayout::createPartitions( Device* dev,
             part = KPMHelpers::createNewEncryptedPartition( parent,
                                                             *dev,
                                                             role,
-                                                            entry.partFileSystem,
+                                                            correctFS( entry.partFileSystem ),
                                                             entry.partLabel,
                                                             currentSector,
                                                             currentSector + sectors - 1,
diff --git a/src/modules/partition/core/PartitionLayout.h b/src/modules/partition/core/PartitionLayout.h
index 6e0c73f8f..c4c26d9f1 100644
--- a/src/modules/partition/core/PartitionLayout.h
+++ b/src/modules/partition/core/PartitionLayout.h
@@ -87,11 +87,28 @@ public:
      *
      * @p config is a list of partition entries (in QVariant form,
      * read from YAML). If no entries are given, then a single
-     * partition is created with the given @p defaultFsType
+     * partition is created with type Unkown.
+     *
+     * Any partitions with FS type Unknown will get the default filesystem
+     * that is set at **apply** time (e.g. when createPartitions() is
+     * called as well.
+     *
+     * @see setDefaultFsType()
      */
     void init( FileSystem::Type defaultFsType, const QVariantList& config );
+    /** @brief add an entry as if it had been listed in the config
+     *
+     * The same comments about filesystem type apply.
+     */
     bool addEntry( const PartitionEntry& entry );
 
+    /** @brief set the default filesystem type
+     *
+     * Any partitions in the layout with type Unknown will get
+     * the default type when createPartitions() is called.
+     */
+    void setDefaultFsType( FileSystem::Type defaultFsType );
+
     /**
      * @brief Apply the current partition layout to the selected drive space.
      * @return  A list of Partition objects.
@@ -105,6 +122,7 @@ public:
 
 private:
     QList< PartitionEntry > m_partLayout;
+    FileSystem::Type m_defaultFsType = FileSystem::Type::Unknown;
 };
 
 #endif /* PARTITIONLAYOUT_H */
diff --git a/src/modules/partition/core/PartitionModel.cpp b/src/modules/partition/core/PartitionModel.cpp
index b4ea57adb..e310eee5e 100644
--- a/src/modules/partition/core/PartitionModel.cpp
+++ b/src/modules/partition/core/PartitionModel.cpp
@@ -327,5 +327,5 @@ PartitionModel::partitionForIndex( const QModelIndex& index ) const
 void
 PartitionModel::update()
 {
-    emit dataChanged( index( 0, 0 ), index( rowCount() - 1, columnCount() - 1 ) );
+    Q_EMIT dataChanged( index( 0, 0 ), index( rowCount() - 1, columnCount() - 1 ) );
 }
diff --git a/src/modules/partition/core/PartitionModel.h b/src/modules/partition/core/PartitionModel.h
index 433fa0620..ba5e258a3 100644
--- a/src/modules/partition/core/PartitionModel.h
+++ b/src/modules/partition/core/PartitionModel.h
@@ -41,7 +41,7 @@ public:
     /**
      * This helper class must be instantiated on the stack *before* making
      * changes to the device represented by this model. It will cause the model
-     * to emit modelAboutToBeReset() when instantiated and modelReset() when
+     * to Q_EMIT modelAboutToBeReset() when instantiated and modelReset() when
      * destructed.
      */
     class ResetHelper
diff --git a/src/modules/partition/gui/ChoicePage.cpp b/src/modules/partition/gui/ChoicePage.cpp
index d2f5c99e7..6438724e8 100644
--- a/src/modules/partition/gui/ChoicePage.cpp
+++ b/src/modules/partition/gui/ChoicePage.cpp
@@ -11,15 +11,9 @@
 
 #include "ChoicePage.h"
 
-#include "BootInfoWidget.h"
-#include "DeviceInfoWidget.h"
-#include "PartitionBarsView.h"
-#include "PartitionLabelsView.h"
-#include "PartitionSplitterWidget.h"
-#include "ReplaceWidget.h"
-#include "ScanningDialog.h"
+#include "Config.h"
+
 #include "core/BootLoaderModel.h"
-#include "core/Config.h"
 #include "core/DeviceModel.h"
 #include "core/KPMHelpers.h"
 #include "core/OsproberEntry.h"
@@ -28,6 +22,13 @@
 #include "core/PartitionCoreModule.h"
 #include "core/PartitionInfo.h"
 #include "core/PartitionModel.h"
+#include "gui/BootInfoWidget.h"
+#include "gui/DeviceInfoWidget.h"
+#include "gui/PartitionBarsView.h"
+#include "gui/PartitionLabelsView.h"
+#include "gui/PartitionSplitterWidget.h"
+#include "gui/ReplaceWidget.h"
+#include "gui/ScanningDialog.h"
 
 #include "Branding.h"
 #include "GlobalStorage.h"
@@ -269,6 +270,15 @@ ChoicePage::setupChoices()
         m_eraseButton->addOptionsComboBox( m_eraseSwapChoiceComboBox );
     }
 
+    if ( m_config->eraseFsTypes().count() > 1)
+    {
+        m_eraseFsTypesChoiceComboBox = new QComboBox;
+        m_eraseFsTypesChoiceComboBox->addItems(m_config->eraseFsTypes());
+        connect( m_eraseFsTypesChoiceComboBox, &QComboBox::currentTextChanged, m_config, &Config::setEraseFsTypeChoice );
+        connect( m_config, &Config::eraseModeFilesystemChanged, this, &ChoicePage::onActionChanged );
+        m_eraseButton->addOptionsComboBox( m_eraseFsTypesChoiceComboBox );
+    }
+
     m_itemsLayout->addWidget( m_alongsideButton );
     m_itemsLayout->addWidget( m_replaceButton );
     m_itemsLayout->addWidget( m_eraseButton );
@@ -293,7 +303,7 @@ ChoicePage::setupChoices()
             m_config->setInstallChoice( id );
             updateNextEnabled();
 
-            emit actionChosen();
+            Q_EMIT actionChosen();
         }
         else  // An action was unpicked, either on its own or because of another selection.
         {
@@ -303,7 +313,7 @@ ChoicePage::setupChoices()
                 m_config->setInstallChoice( InstallChoice::NoChoice );
                 updateNextEnabled();
 
-                emit actionChosen();
+                Q_EMIT actionChosen();
             }
         }
     } );
@@ -426,8 +436,8 @@ ChoicePage::continueApplyDeviceChoice()
         checkInstallChoiceRadioButton( m_config->installChoice() );
     }
 
-    emit actionChosen();
-    emit deviceChosen();
+    Q_EMIT actionChosen();
+    Q_EMIT deviceChosen();
 }
 
 
@@ -465,9 +475,8 @@ ChoicePage::applyActionChoice( InstallChoice choice )
     case InstallChoice::Erase:
     {
         auto gs = Calamares::JobQueue::instance()->globalStorage();
-
         PartitionActions::Choices::AutoPartitionOptions options { gs->value( "defaultPartitionTableType" ).toString(),
-                                                                  gs->value( "defaultFileSystemType" ).toString(),
+                                                                  m_config->eraseFsType(),
                                                                   m_encryptWidget->passphrase(),
                                                                   gs->value( "efiSystemPartition" ).toString(),
                                                                   CalamaresUtils::GiBtoBytes(
@@ -483,14 +492,14 @@ ChoicePage::applyActionChoice( InstallChoice choice )
                 } ),
                 [=] {
                     PartitionActions::doAutopartition( m_core, selectedDevice(), options );
-                    emit deviceChosen();
+                    Q_EMIT deviceChosen();
                 },
                 this );
         }
         else
         {
             PartitionActions::doAutopartition( m_core, selectedDevice(), options );
-            emit deviceChosen();
+            Q_EMIT deviceChosen();
         }
     }
     break;
@@ -1595,7 +1604,7 @@ ChoicePage::updateNextEnabled()
     if ( enabled != m_nextEnabled )
     {
         m_nextEnabled = enabled;
-        emit nextStatusChanged( enabled );
+        Q_EMIT nextStatusChanged( enabled );
     }
 }
 
diff --git a/src/modules/partition/gui/ChoicePage.h b/src/modules/partition/gui/ChoicePage.h
index 89bd775d7..5e0a24d43 100644
--- a/src/modules/partition/gui/ChoicePage.h
+++ b/src/modules/partition/gui/ChoicePage.h
@@ -15,7 +15,7 @@
 #include "ui_ChoicePage.h"
 
 
-#include "core/Config.h"
+#include "Config.h"
 #include "core/OsproberEntry.h"
 
 #include <QMutex>
@@ -138,7 +138,9 @@ private:
     Calamares::PrettyRadioButton* m_eraseButton;
     Calamares::PrettyRadioButton* m_replaceButton;
     Calamares::PrettyRadioButton* m_somethingElseButton;
-    QComboBox* m_eraseSwapChoiceComboBox;  // UI, see also m_eraseSwapChoice
+    QComboBox* m_eraseSwapChoiceComboBox = nullptr;  // UI, see also Config's swap choice
+    QComboBox* m_eraseFsTypesChoiceComboBox = nullptr;  // UI, see also Config's erase-mode FS
+
 
     DeviceInfoWidget* m_deviceInfoWidget;
 
diff --git a/src/modules/partition/gui/CreatePartitionDialog.cpp b/src/modules/partition/gui/CreatePartitionDialog.cpp
index 5ebe15336..cdc9992b9 100644
--- a/src/modules/partition/gui/CreatePartitionDialog.cpp
+++ b/src/modules/partition/gui/CreatePartitionDialog.cpp
@@ -92,7 +92,7 @@ CreatePartitionDialog::CreatePartitionDialog( Device* device,
 
     // File system; the config value is translated (best-effort) to a type
     FileSystem::Type defaultFSType;
-    QString untranslatedFSName = PartUtils::findFS(
+    QString untranslatedFSName = PartUtils::canonicalFilesystemName(
         Calamares::JobQueue::instance()->globalStorage()->value( "defaultFileSystemType" ).toString(), &defaultFSType );
     if ( defaultFSType == FileSystem::Type::Unknown )
     {
diff --git a/src/modules/partition/gui/EditExistingPartitionDialog.cpp b/src/modules/partition/gui/EditExistingPartitionDialog.cpp
index e2d7ac5ba..411d6d0dc 100644
--- a/src/modules/partition/gui/EditExistingPartitionDialog.cpp
+++ b/src/modules/partition/gui/EditExistingPartitionDialog.cpp
@@ -97,7 +97,7 @@ EditExistingPartitionDialog::EditExistingPartitionDialog( Device* device,
     m_ui->fileSystemComboBox->addItems( fsNames );
 
     FileSystem::Type defaultFSType;
-    QString untranslatedFSName = PartUtils::findFS(
+    QString untranslatedFSName = PartUtils::canonicalFilesystemName(
         Calamares::JobQueue::instance()->globalStorage()->value( "defaultFileSystemType" ).toString(), &defaultFSType );
     if ( defaultFSType == FileSystem::Type::Unknown )
     {
diff --git a/src/modules/partition/gui/EncryptWidget.cpp b/src/modules/partition/gui/EncryptWidget.cpp
index 7f648491a..ee50e7d66 100644
--- a/src/modules/partition/gui/EncryptWidget.cpp
+++ b/src/modules/partition/gui/EncryptWidget.cpp
@@ -136,7 +136,7 @@ EncryptWidget::updateState()
     if ( newState != m_state )
     {
         m_state = newState;
-        emit stateChanged( m_state );
+        Q_EMIT stateChanged( m_state );
     }
 }
 
diff --git a/src/modules/partition/gui/PartitionSplitterWidget.cpp b/src/modules/partition/gui/PartitionSplitterWidget.cpp
index 93c77bb69..0cafe7814 100644
--- a/src/modules/partition/gui/PartitionSplitterWidget.cpp
+++ b/src/modules/partition/gui/PartitionSplitterWidget.cpp
@@ -225,7 +225,7 @@ PartitionSplitterWidget::setSplitPartition( const QString& path, qint64 minSize,
         }
     }
 
-    emit partitionResized( m_itemToResize.itemPath, m_itemToResize.size, m_itemToResizeNext.size );
+    Q_EMIT partitionResized( m_itemToResize.itemPath, m_itemToResize.size, m_itemToResizeNext.size );
 
     cDebug() << "Items updated. Status:";
     foreach ( const PartitionSplitterItem& item, m_items )
@@ -374,7 +374,7 @@ PartitionSplitterWidget::mouseMoveEvent( QMouseEvent* event )
 
         repaint();
 
-        emit partitionResized( itemPath, m_itemToResize.size, m_itemToResizeNext.size );
+        Q_EMIT partitionResized( itemPath, m_itemToResize.size, m_itemToResizeNext.size );
     }
     else
     {
diff --git a/src/modules/partition/gui/ReplaceWidget.cpp b/src/modules/partition/gui/ReplaceWidget.cpp
index 078eb4de7..94f527646 100644
--- a/src/modules/partition/gui/ReplaceWidget.cpp
+++ b/src/modules/partition/gui/ReplaceWidget.cpp
@@ -311,7 +311,7 @@ ReplaceWidget::setNextEnabled( bool enabled )
     }
 
     m_nextEnabled = enabled;
-    emit nextStatusChanged( enabled );
+    Q_EMIT nextStatusChanged( enabled );
 }
 
 
diff --git a/src/modules/partition/gui/ScanningDialog.cpp b/src/modules/partition/gui/ScanningDialog.cpp
index cd22bb861..4dffa922b 100644
--- a/src/modules/partition/gui/ScanningDialog.cpp
+++ b/src/modules/partition/gui/ScanningDialog.cpp
@@ -68,5 +68,5 @@ void
 ScanningDialog::setVisible( bool visible )
 {
     QDialog::setVisible( visible );
-    emit visibilityChanged();
+    Q_EMIT visibilityChanged();
 }
diff --git a/src/modules/partition/jobs/PartitionJob.cpp b/src/modules/partition/jobs/PartitionJob.cpp
index 3bdb05ebd..ca9b00944 100644
--- a/src/modules/partition/jobs/PartitionJob.cpp
+++ b/src/modules/partition/jobs/PartitionJob.cpp
@@ -25,5 +25,5 @@ PartitionJob::iprogress( int percent )
     {
         percent = 100;
     }
-    emit progress( qreal( percent / 100.0 ) );
+    Q_EMIT progress( qreal( percent / 100.0 ) );
 }
diff --git a/src/modules/partition/partition.conf b/src/modules/partition/partition.conf
index 7330f92b3..3213e0d33 100644
--- a/src/modules/partition/partition.conf
+++ b/src/modules/partition/partition.conf
@@ -113,12 +113,11 @@ initialSwapChoice: none
 # Restrict the installation on disks that match the type of partition
 # tables that are specified.
 #
-# Suggested values: msdos, gpt
-# If nothing is specified, Calamares defaults to both "msdos" and "mbr".
+# Possible values: msdos, gpt. Names are case-sensitive and defined by KPMCore.
+#
+# If nothing is specified, Calamares defaults to both "msdos" and "gpt".
 #
-# Names are case-sensitive and defined by KPMCore.
 # requiredPartitionTableType: gpt
-# or,
 # requiredPartitionTableType:
 #     - msdos
 #     - gpt
@@ -139,6 +138,17 @@ initialSwapChoice: none
 # Names are case-sensitive and defined by KPMCore.
 defaultFileSystemType:  "ext4"
 
+# Selectable filesystem type, used when "erase" is done.
+#
+# When erasing the disk, the *defaultFileSystemType* is used (see
+# above), but it is also possible to give users a choice:
+# list suitable filesystems here. A drop-down is provided
+# to pick which is the filesystems will be used.
+#
+# The value *defaultFileSystemType* is added to this list (with a warning)
+# if not present; the default pick is the *defaultFileSystemType*.
+availableFileSystemTypes:  ["ext4", "btrfs", "f2fs"]
+
 # Show/hide LUKS related functionality in automated partitioning modes.
 # Disable this if you choose not to deploy early unlocking support in GRUB2
 # and/or your distribution's initramfs solution.
@@ -205,7 +215,12 @@ defaultFileSystemType:  "ext4"
 #   - uuid: partition uuid (optional parameter; gpt only; requires KPMCore >= 4.2.0)
 #   - type: partition type (optional parameter; gpt only; requires KPMCore >= 4.2.0)
 #   - attributes: partition attributes (optional parameter; gpt only; requires KPMCore >= 4.2.0)
-#   - filesystem: filesystem type (optional parameter; fs not created if "unformatted" or unset)
+#   - filesystem: filesystem type (optional parameter)
+#       - if not set at all, treat as "unformatted"
+#       - if "unformatted", no filesystem will be created
+#       - if "unknown" (or an unknown FS name, like "elephant") then the
+#         default filesystem type, or the user's choice, will be applied instead
+#         of "unknown" (e.g. the user might pick ext4, or xfs).
 #   - mountPoint: partition mount point (optional parameter; not mounted if unset)
 #   - size: partition size in bytes (append 'K', 'M' or 'G' for KiB, MiB or GiB)
 #           or
diff --git a/src/modules/partition/partition.schema.yaml b/src/modules/partition/partition.schema.yaml
index 16cc08319..6c65e8ae7 100644
--- a/src/modules/partition/partition.schema.yaml
+++ b/src/modules/partition/partition.schema.yaml
@@ -18,6 +18,8 @@ properties:
     alwaysShowPartitionLabels: { type: boolean, default: true }
 
     defaultFileSystemType: { type: string }
+    availableFileSystemTypes: { type: array, items: { type: string } }
+
     enableLuksAutomatedPartitioning: { type: boolean, default: false }
     allowManualPartitioning: { type: boolean, default: true }
     partitionLayout: { type: array }  # TODO: specify items