diff --git a/configure.ac b/configure.ac
index 185e4d08623..1e66acf52fe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2797,7 +2797,11 @@ gtk3_pkg_errors=
 if test "${opsys}" != "mingw32"; then
   if test "${with_gtk3}" = "yes" || test "${with_gtk}" = "yes" || test "$USE_X_TOOLKIT" = "maybe"; then
     GLIB_REQUIRED=2.37.5
-    GTK_REQUIRED=3.10
+    if test "${window_system}" = "x"; then
+      GTK_REQUIRED=3.10
+    else
+      GTK_REQUIRED=3.20
+    fi
     GTK_MODULES="gtk+-3.0 >= $GTK_REQUIRED glib-2.0 >= $GLIB_REQUIRED"
 
     dnl Checks for libraries.
diff --git a/src/pgtkterm.c b/src/pgtkterm.c
index 566fc1f03d1..0bb41cb4463 100644
--- a/src/pgtkterm.c
+++ b/src/pgtkterm.c
@@ -5008,7 +5008,6 @@ pgtk_any_window_to_frame (GdkWindow * window)
 static gboolean
 pgtk_handle_event (GtkWidget *widget, GdkEvent *event, gpointer *data)
 {
-#if GTK_CHECK_VERSION (3, 18, 0)
   struct frame *f;
   union buffered_input_event inev;
   GtkWidget *frame_widget;
@@ -5045,7 +5044,6 @@ pgtk_handle_event (GtkWidget *widget, GdkEvent *event, gpointer *data)
 
       return TRUE;
     }
-#endif
   return FALSE;
 }