diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
index a1f17019fb..3d74f59729 100644
--- a/libavformat/rtpdec.c
+++ b/libavformat/rtpdec.c
@@ -424,7 +424,7 @@ int ff_rtp_send_rtcp_feedback(RTPDemuxContext *s, URLContext *fd,
     AVIOContext *pb;
     uint8_t *buf;
     int64_t now;
-    uint16_t first_missing, missing_mask;
+    uint16_t first_missing = 0, missing_mask = 0;
 
     if (!fd && !avio)
         return -1;
diff --git a/libavformat/rtpdec_vp8.c b/libavformat/rtpdec_vp8.c
index 623d3599f5..b4b4f2207d 100644
--- a/libavformat/rtpdec_vp8.c
+++ b/libavformat/rtpdec_vp8.c
@@ -82,7 +82,7 @@ static int vp8_handle_packet(AVFormatContext *ctx, PayloadContext *vp8,
         keyidx_present = 0;
     int pictureid = -1, pictureid_mask = 0;
     int returned_old_frame = 0;
-    uint32_t old_timestamp;
+    uint32_t old_timestamp = 0;
 
     if (!buf) {
         if (vp8->data) {