diff --git a/src/edit.c b/src/edit.c
index 672028b..e9a994f 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -2023,7 +2023,7 @@
      * Only use mod_mask for special keys, to avoid things like <S-Space>,
      * unless 'allow_modmask' is TRUE.
      */
-#ifdef MACOS_X
+#if defined(MACOS_X) || defined(FEAT_GUI_GTK)
     // Command-key never produces a normal key
     if (mod_mask & MOD_MASK_CMD)
 	allow_modmask = TRUE;