diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 0a837d4e5a..52d0425507 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -1793,6 +1793,7 @@ AVInputFormat ff_avi_demuxer = {
     .name           = "avi",
     .long_name      = NULL_IF_CONFIG_SMALL("AVI (Audio Video Interleaved)"),
     .priv_data_size = sizeof(AVIContext),
+    .extensions     = "avi",
     .read_probe     = avi_probe,
     .read_header    = avi_read_header,
     .read_packet    = avi_read_packet,
diff --git a/libavformat/mov.c b/libavformat/mov.c
index e025133266..c711be1609 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3709,6 +3709,7 @@ AVInputFormat ff_mov_demuxer = {
     .name           = "mov,mp4,m4a,3gp,3g2,mj2",
     .long_name      = NULL_IF_CONFIG_SMALL("QuickTime / MOV"),
     .priv_data_size = sizeof(MOVContext),
+    .extensions     = "mov,mp4,m4a,3gp,3g2,mj2",
     .read_probe     = mov_probe,
     .read_header    = mov_read_header,
     .read_packet    = mov_read_packet,