diff --git a/mythtv/programs/mythcommflag/ClassicCommDetector.cpp b/mythtv/programs/mythcommflag/ClassicCommDetector.cpp
index 954720d9850..74097c7c640 100644
--- a/mythtv/programs/mythcommflag/ClassicCommDetector.cpp
+++ b/mythtv/programs/mythcommflag/ClassicCommDetector.cpp
@@ -740,7 +740,7 @@ void ClassicCommDetector::ProcessFrame(VideoFrame *frame,
     int rightDarkCol = width - commDetectBorder - 1;
     FrameInfoEntry fInfo;
 
-    if (!frame || frame_number == -1 || frame->codec != FMT_YV12)
+    if (!frame || !(frame->buf) || frame_number == -1 || frame->codec != FMT_YV12)
     {
         VERBOSE(VB_COMMFLAG, "CommDetect: Invalid video frame or codec, "
                 "unable to process frame.");