diff --git a/aegisub/src/ass_file.cpp b/aegisub/src/ass_file.cpp
index e57716bd1..8ba8b8c97 100644
--- a/aegisub/src/ass_file.cpp
+++ b/aegisub/src/ass_file.cpp
@@ -654,7 +654,7 @@ int AssFile::Commit(wxString desc, int type, int amendId, AssEntry *single_line)
 	UndoStack.push_back(*this);
 
 	// Cap depth
-	int depth = OPT_GET("Limits/Undo Levels")->GetInt();
+	int depth = std::max<int>(OPT_GET("Limits/Undo Levels")->GetInt(), 2);
 	while ((int)UndoStack.size() > depth) {
 		UndoStack.pop_front();
 	}
diff --git a/aegisub/src/preferences.cpp b/aegisub/src/preferences.cpp
index 8dd137db4..3231a8767 100644
--- a/aegisub/src/preferences.cpp
+++ b/aegisub/src/preferences.cpp
@@ -111,7 +111,7 @@ General::General(wxTreebook *book, Preferences *parent): OptionPage(book, parent
 	wxArrayString autoload_modes_arr(3, autoload_modes);
 	OptionChoice(general, _("Automatically load linked files"), autoload_modes_arr, "App/Auto/Load Linked Files");
 	OptionAdd(general, _("Toolbar Icon Size"), "App/Toolbar Icon Size");
-	OptionAdd(general, _("Undo Levels"), "Limits/Undo Levels");
+	OptionAdd(general, _("Undo Levels"), "Limits/Undo Levels", 2);
 
 	wxFlexGridSizer *recent = PageSizer(_("Recently Used Lists"));
 	OptionAdd(recent, _("Files"), "Limits/MRU");