diff --git a/histogram.cc b/histogram.cc
index c1d13d9..e576421 100644
--- a/histogram.cc
+++ b/histogram.cc
@@ -115,7 +115,7 @@ void histogram_update(VideoFrame *vf) {
 
 	// save some time
 	static int to = 0;
-	if ((++to) % 8 == 0) to = 0;
+	if ((++to) % 8 == 0) return;
 
 	int chan, i, x, y;