diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
index ebd5402bce..2e2cbf5477 100644
--- a/libavformat/rtpdec.c
+++ b/libavformat/rtpdec.c
@@ -587,7 +587,8 @@ void ff_rtp_parse_set_crypto(RTPDemuxContext *s, const char *suite,
 }
 
 static int rtp_set_prft(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestamp) {
-    int64_t rtcp_time, delta_timestamp, delta_time;
+    int64_t rtcp_time, delta_time;
+    int32_t delta_timestamp;
 
     AVProducerReferenceTime *prft =
         (AVProducerReferenceTime *) av_packet_new_side_data(
@@ -596,7 +597,7 @@ static int rtp_set_prft(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestamp) {
         return AVERROR(ENOMEM);
 
     rtcp_time = ff_parse_ntp_time(s->last_rtcp_ntp_time) - NTP_OFFSET_US;
-    delta_timestamp = (int64_t)timestamp - (int64_t)s->last_rtcp_timestamp;
+    delta_timestamp = (int32_t)(timestamp - s->last_rtcp_timestamp);
     delta_time = av_rescale_q(delta_timestamp, s->st->time_base, AV_TIME_BASE_Q);
 
     prft->wallclock = rtcp_time + delta_time;