diff --git a/src/gui_gtk_x11.c b/src/gui_gtk_x11.c
index 74b6de9..baaed59 100644
--- a/src/gui_gtk_x11.c
+++ b/src/gui_gtk_x11.c
@@ -948,6 +948,10 @@
 	modifiers |= MOD_MASK_CTRL;
     if (state & GDK_MOD1_MASK)
 	modifiers |= MOD_MASK_ALT;
+#ifdef GDK_SUPER_MASK
+    if (state & GDK_SUPER_MASK)
+	modifiers |= MOD_MASK_META;
+#endif
     if (state & GDK_MOD4_MASK)
 	modifiers |= MOD_MASK_META;
 
@@ -1121,7 +1125,11 @@
      * Don't do this for double-byte encodings, it turns the char into a lead
      * byte. */
     if (len == 1
-	    && (state & GDK_MOD1_MASK)
+	    && ((state & GDK_MOD1_MASK)
+#ifdef GDK_SUPER_MASK
+		|| (state & GDK_SUPER_MASK)
+#endif
+		)
 	    && !(key_sym == GDK_BackSpace || key_sym == GDK_Delete)
 	    && (string[0] & 0x80) == 0
 	    && !(key_sym == GDK_Tab && (state & GDK_SHIFT_MASK))
@@ -1182,7 +1190,11 @@
 	    || key_sym == GDK_Escape || key_sym == GDK_KP_Tab
 	    || key_sym == GDK_ISO_Enter || key_sym == GDK_3270_Enter
 #ifdef FEAT_MBYTE
-	    || (enc_dbcs && len == 1 && (state & GDK_MOD1_MASK))
+	    || (enc_dbcs && len == 1 && ((state & GDK_MOD1_MASK)
+# ifdef GDK_SUPER_MASK
+		    || (state & GDK_SUPER_MASK)
+# endif
+		    ))
 #endif
 	    )
     {
@@ -2214,10 +2226,10 @@
  * necessary.
  */
     static void
-sm_client_check_changed_any(GnomeClient	    *client,
+sm_client_check_changed_any(GnomeClient	    *client UNUSED,
 			    gint	    key,
-			    GnomeDialogType type,
-			    gpointer	    data)
+			    GnomeDialogType type UNUSED,
+			    gpointer	    data UNUSED)
 {
     cmdmod_T	save_cmdmod;
     gboolean	shutdown_cancelled;
@@ -2322,12 +2334,12 @@
  */
     static gboolean
 sm_client_save_yourself(GnomeClient	    *client,
-			gint		    phase,
-			GnomeSaveStyle	    save_style,
-			gboolean	    shutdown,
+			gint		    phase UNUSED,
+			GnomeSaveStyle	    save_style UNUSED,
+			gboolean	    shutdown UNUSED,
 			GnomeInteractStyle  interact_style,
-			gboolean	    fast,
-			gpointer	    data)
+			gboolean	    fast UNUSED,
+			gpointer	    data UNUSED)
 {
     static const char	suffix[] = "-session.vim";
     char		*session_file;
@@ -2408,7 +2420,7 @@
  * is happening).
  */
     static void
-sm_client_die(GnomeClient *client, gpointer data)
+sm_client_die(GnomeClient *client UNUSED, gpointer data UNUSED)
 {
     /* Don't write messages to the GUI anymore */
     full_screen = FALSE;