diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index b6e00115bb..23401a44e8 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -10984,7 +10984,10 @@ gtk_widget_get_scale_factor (GtkWidget *widget)
   display = gtk_widget_get_display (widget);
   monitor = gdk_display_get_monitor (display, 0);
 
-  return gdk_monitor_get_scale_factor (monitor);
+  if (monitor)
+    return gdk_monitor_get_scale_factor (monitor);
+
+  return 1;
 }
 
 /**