diff --git a/gnucash/import-export/CMakeLists.txt b/gnucash/import-export/CMakeLists.txt
index 739dbf0489..40b93d2793 100644
--- a/gnucash/import-export/CMakeLists.txt
+++ b/gnucash/import-export/CMakeLists.txt
@@ -17,7 +17,7 @@ set (generic_import_SOURCES
   import-account-matcher.cpp
   import-commodity-matcher.cpp
   import-backend.cpp
-  import-format-dialog.c
+  import-format-dialog.cpp
   import-match-picker.cpp
   import-parse.c
   import-utilities.c
diff --git a/gnucash/import-export/import-format-dialog.c b/gnucash/import-export/import-format-dialog.cpp
similarity index 98%
rename from gnucash/import-export/import-format-dialog.c
rename to gnucash/import-export/import-format-dialog.cpp
index ecd495da81..93cabb6f2c 100644
--- a/gnucash/import-export/import-format-dialog.c
+++ b/gnucash/import-export/import-format-dialog.cpp
@@ -38,7 +38,7 @@
 static void
 option_changed_cb (GtkWidget *widget, gpointer index_p)
 {
-    gint *my_index = index_p;
+    auto my_index = static_cast<gint*>(index_p);
     *my_index = gtk_combo_box_get_active(GTK_COMBO_BOX(widget));
 }
 
@@ -139,7 +139,7 @@ gnc_import_choose_fmt(const char* msg, GncImportFormat fmts, gpointer data)
     GtkWidget *dialog;
     GtkWidget *widget;
 
-    g_return_val_if_fail(fmts, FALSE);
+    g_return_val_if_fail (fmts, GNCIF_NONE);
 
     /* if there is only one format available, just return it */
     if (!(fmts & (fmts - 1)))
diff --git a/po/POTFILES.in b/po/POTFILES.in
index fd6e3ea360..5f5c90b545 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -349,7 +349,7 @@ gnucash/import-export/customer-import/gnc-plugin-customer-import.c
 gnucash/import-export/import-account-matcher.cpp
 gnucash/import-export/import-backend.cpp
 gnucash/import-export/import-commodity-matcher.cpp
-gnucash/import-export/import-format-dialog.c
+gnucash/import-export/import-format-dialog.cpp
 gnucash/import-export/import-main-matcher.cpp
 gnucash/import-export/import-match-picker.cpp
 gnucash/import-export/import-parse.c