diff --git a/libavformat/mov.c b/libavformat/mov.c
index 45367d39f7..764a7b1411 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2506,7 +2506,7 @@ static int mov_read_ctts(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         av_log(c->fc, AV_LOG_TRACE, "count=%d, duration=%d\n",
                 count, duration);
 
-        if (FFABS(duration) > (1<<28) && i+2<entries) {
+        if (FFNABS(duration) < -(1<<28) && i+2<entries) {
             av_log(c->fc, AV_LOG_WARNING, "CTTS invalid\n");
             av_freep(&sc->ctts_data);
             sc->ctts_count = 0;