diff --git a/lasertrack.py b/lasertrack.py
index 86445bd..c39338c 100755
--- a/lasertrack.py
+++ b/lasertrack.py
@@ -80,7 +80,8 @@ class VideoSource(RgbProcessorAdapter):
 		cap = cv2.VideoCapture(self.fileName)
 		while not self.cancel:
 			ret, frame = cap.read()
-			self.write(frame)
+			if ret:
+				self.write(frame)
 			time.sleep(1.0/self.framerate)