diff --git a/src/modules/displaymanager/displaymanager.conf b/src/modules/displaymanager/displaymanager.conf
index fe1d2bc14..c3e0e1160 100644
--- a/src/modules/displaymanager/displaymanager.conf
+++ b/src/modules/displaymanager/displaymanager.conf
@@ -25,7 +25,11 @@ displaymanagers:
 #  - *desktopFile* a .desktop filename
 #
 # If this is **not** set, then Calamares will look for installed
-# DE's and pick the first one it finds.
+# DE's and pick the first one it finds that is actually installed.
+#
+# If this **is** set, and the *executable* key doesn't point to
+# an installed file, then the .desktop file's TryExec key is
+# used instead.
 #
 
 #defaultDesktopEnvironment: