diff --git a/libav/asf.c b/libav/asf.c
index adc2437ea4..23a2cb3471 100644
--- a/libav/asf.c
+++ b/libav/asf.c
@@ -131,8 +131,10 @@ CodecTag codec_asf_bmp_tags[] = {
     { CODEC_ID_MPEG4, MKTAG('D', 'I', 'V', 'X') },
     { CODEC_ID_MPEG4, MKTAG('d', 'i', 'v', 'x') },
     { CODEC_ID_MPEG4, MKTAG(0x04, 0, 0, 0) }, /* some broken avi use this */
-    { CODEC_ID_MSMPEG4, MKTAG('M', 'P', '4', '3') }, /* default signature when using MSMPEG4 */
-    { CODEC_ID_MSMPEG4, MKTAG('D', 'I', 'V', '3') }, 
+    { CODEC_ID_MSMPEG4V3, MKTAG('M', 'P', '4', '3') }, /* default signature when using MSMPEG4 */ 
+    { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '3') },
+    { CODEC_ID_MSMPEG4V2, MKTAG('M', 'P', '4', '2') }, 
+    { CODEC_ID_MSMPEG4V1, MKTAG('M', 'P', '4', '1') }, 
     { 0, 0 },
 };
 
diff --git a/libav/avienc.c b/libav/avienc.c
index e1944e8c11..52fdea237e 100644
--- a/libav/avienc.c
+++ b/libav/avienc.c
@@ -63,8 +63,10 @@ CodecTag codec_bmp_tags[] = {
     { CODEC_ID_MPEG4, MKTAG('D', 'I', 'V', 'X') },
     { CODEC_ID_MPEG4, MKTAG('d', 'i', 'v', 'x') },
     { CODEC_ID_MPEG4, MKTAG(0x04, 0, 0, 0) }, /* some broken avi use this */
-    { CODEC_ID_MSMPEG4, MKTAG('D', 'I', 'V', '3') }, /* default signature when using MSMPEG4 */
-    { CODEC_ID_MSMPEG4, MKTAG('M', 'P', '4', '3') }, 
+    { CODEC_ID_MSMPEG4V3, MKTAG('D', 'I', 'V', '3') }, /* default signature when using MSMPEG4 */
+    { CODEC_ID_MSMPEG4V3, MKTAG('M', 'P', '4', '3') }, 
+    { CODEC_ID_MSMPEG4V2, MKTAG('M', 'P', '4', '2') }, 
+    { CODEC_ID_MSMPEG4V1, MKTAG('M', 'P', '4', '1') }, 
     { 0, 0 },
 };