diff --git a/src/backends/x11/meta-gpu-xrandr.c b/src/backends/x11/meta-gpu-xrandr.c
index 404629024..f8f4b1a73 100644
--- a/src/backends/x11/meta-gpu-xrandr.c
+++ b/src/backends/x11/meta-gpu-xrandr.c
@@ -92,12 +92,12 @@ calculate_xrandr_refresh_rate (XRRModeInfo *xmode)
   float h_total;
   float v_total;
 
+  if (xmode->hTotal == 0 || xmode->vTotal == 0)
+    return 0.0;
+
   h_total = (float) xmode->hTotal;
   v_total = (float) xmode->vTotal;
 
-  if (h_total == 0.0 || v_total == 0.0)
-    return 0.0;
-
   if (xmode->modeFlags & RR_DoubleScan)
     v_total *= 2.0;