diff --git a/doc/userguide/upgrade.rst b/doc/userguide/upgrade.rst
index 282c5a0cf1..e8a3410c04 100644
--- a/doc/userguide/upgrade.rst
+++ b/doc/userguide/upgrade.rst
@@ -95,6 +95,9 @@ Major changes
   will need to be set before external modules can be loaded. See the
   new default configuration file or :ref:`lua-output-yaml` for more
   details.
+- If the configuration value ``ftp.memcap`` is invalid, Suricata will set it to ``0`` which means
+  no limit will be placed. In previous Suricata  releases, Suricata would terminate execution. A
+  warning message will be displayed `Invalid value <value> for ftp.memcap` when this occurs.
 
 Removals
 ~~~~~~~~
diff --git a/rust/src/ftp/ftp.rs b/rust/src/ftp/ftp.rs
index 2cc4566077..3963a2adfa 100644
--- a/rust/src/ftp/ftp.rs
+++ b/rust/src/ftp/ftp.rs
@@ -19,6 +19,7 @@ use std;
 use std::ffi::CString;
 use std::os::raw::{c_char, c_int, c_void};
 
+use crate::conf::{conf_get, get_memval};
 use crate::ftp::constant::*;
 use lazy_static::lazy_static;
 
@@ -182,6 +183,49 @@ impl FtpTransferCmd {
     }
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn SCFTPGetConfigValues(
+    memcap: *mut u64, max_tx: *mut u32, max_line_len: *mut u32,
+) {
+    if let Some(val) = conf_get("app-layer.protocols.ftp.memcap") {
+        if let Ok(v) = get_memval(val) {
+            *memcap = v;
+            SCLogConfig!("FTP memcap: {}", v);
+        } else {
+            SCLogWarning!(
+                "Invalid value {} for ftp.memcap; defaulting to {}",
+                val,
+                *memcap
+            );
+        }
+    }
+    if let Some(val) = conf_get("app-layer.protocols.ftp.max-tx") {
+        if let Ok(v) = val.parse::<u32>() {
+            *max_tx = v;
+            SCLogConfig!("FTP max tx: {}", v);
+        } else {
+            SCLogWarning!(
+                "Invalid value {} for ftp.max-tx; defaulting to {}",
+                val,
+                *max_tx
+            );
+        }
+    }
+    // This value is often expressed with a unit suffix, e.g., 5kb, hence get_memval
+    if let Some(val) = conf_get("app-layer.protocols.ftp.max-line-length") {
+        if let Ok(v) = get_memval(val) {
+            *max_line_len = v as u32;
+            SCLogConfig!("FTP max line length: {}", v);
+        } else {
+            SCLogWarning!(
+                "Invalid value {} for ftp.max-line-length; defaulting to {}",
+                val,
+                *max_line_len
+            );
+        }
+    }
+}
+
 /// Returns *mut FtpTransferCmd
 #[no_mangle]
 pub unsafe extern "C" fn SCFTPTransferCmdNew() -> *mut FtpTransferCmd {
diff --git a/src/app-layer-ftp.c b/src/app-layer-ftp.c
index 682ee2b42a..29df14e530 100644
--- a/src/app-layer-ftp.c
+++ b/src/app-layer-ftp.c
@@ -58,41 +58,10 @@ static FTPTransaction *FTPGetOldestTx(const FtpState *, FTPTransaction *);
 
 static void FTPParseMemcap(void)
 {
-    const char *conf_val;
-
-    /** set config values for memcap, prealloc and hash_size */
-    if ((ConfGet("app-layer.protocols.ftp.memcap", &conf_val)) == 1)
-    {
-        if (ParseSizeStringU64(conf_val, &ftp_config_memcap) < 0) {
-            SCLogError("Error parsing ftp.memcap "
-                       "from conf file - %s.  Killing engine",
-                    conf_val);
-            exit(EXIT_FAILURE);
-        }
-        SCLogInfo("FTP memcap: %"PRIu64, ftp_config_memcap);
-    } else {
-        /* default to unlimited */
-        ftp_config_memcap = 0;
-    }
+    SCFTPGetConfigValues(&ftp_config_memcap, &ftp_config_maxtx, &ftp_max_line_len);
 
     SC_ATOMIC_INIT(ftp_memuse);
     SC_ATOMIC_INIT(ftp_memcap);
-
-    if ((ConfGet("app-layer.protocols.ftp.max-tx", &conf_val)) == 1) {
-        if (ParseSizeStringU32(conf_val, &ftp_config_maxtx) < 0) {
-            SCLogError("Error parsing ftp.max-tx "
-                       "from conf file - %s.",
-                    conf_val);
-        }
-        SCLogInfo("FTP max tx: %" PRIu32, ftp_config_maxtx);
-    }
-
-    if ((ConfGet("app-layer.protocols.ftp.max-line-length", &conf_val)) == 1) {
-        if (ParseSizeStringU32(conf_val, &ftp_max_line_len) < 0) {
-            SCLogError("Error parsing ftp.max-line-length from conf file - %s.", conf_val);
-        }
-        SCLogConfig("FTP max line length: %" PRIu32, ftp_max_line_len);
-    }
 }
 
 static void FTPIncrMemuse(uint64_t size)