diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index 6fff2bb132..def89849f5 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -575,7 +575,8 @@ static int decode_info_header(NUTContext *nut)
 
             if (stream_id_plus1 && !strcmp(name, "r_frame_rate")) {
                 sscanf(str_value, "%d/%d", &st->r_frame_rate.num, &st->r_frame_rate.den);
-                if (st->r_frame_rate.num >= 1000LL*st->r_frame_rate.den)
+                if (st->r_frame_rate.num >= 1000LL*st->r_frame_rate.den ||
+                    st->r_frame_rate.num < 0 || st->r_frame_rate.num < 0)
                     st->r_frame_rate.num = st->r_frame_rate.den = 0;
                 continue;
             }