diff --git a/avconv.c b/avconv.c
index 6517c4bcfca0adca82824a5e70adba07a5846de0..c59916e3ed94c597f3b46e88fe64b403aa287f99 100644
--- a/avconv.c
+++ b/avconv.c
@@ -1568,7 +1568,7 @@ static int poll_filters(void)
                                                    AV_TIME_BASE_Q,
                                                    ost->st->codec->time_base);
 
-            if (of->start_time && filtered_frame->pts < of->start_time) {
+            if (of->start_time && filtered_frame->pts < 0) {
                 avfilter_unref_buffer(picref);
                 continue;
             }