diff --git a/gdk/gdkmonitor.c b/gdk/gdkmonitor.c
index 58c238d63b..7875899838 100644
--- a/gdk/gdkmonitor.c
+++ b/gdk/gdkmonitor.c
@@ -404,7 +404,7 @@ gdk_monitor_get_model (GdkMonitor *monitor)
 int
 gdk_monitor_get_scale_factor (GdkMonitor *monitor)
 {
-  g_return_val_if_fail (GDK_IS_MONITOR (monitor), 0);
+  g_return_val_if_fail (GDK_IS_MONITOR (monitor), 1);
 
   return monitor->scale_factor;
 }