diff --git a/subprojects/gst-libav/docs/gst_plugins_cache.json b/subprojects/gst-libav/docs/gst_plugins_cache.json
index e27deefd5b..48ed39b3c8 100644
--- a/subprojects/gst-libav/docs/gst_plugins_cache.json
+++ b/subprojects/gst-libav/docs/gst_plugins_cache.json
@@ -16317,7 +16317,7 @@
                 "long-name": "libav Mobotix MxPEG video decoder",
                 "pad-templates": {
                     "sink": {
-                        "caps": "unknown/unknown:\n",
+                        "caps": "video/x-mxpeg:\n",
                         "direction": "sink",
                         "presence": "always"
                     },
diff --git a/subprojects/gst-libav/ext/libav/gstavcodecmap.c b/subprojects/gst-libav/ext/libav/gstavcodecmap.c
index 2425913c35..8d3f3ee696 100644
--- a/subprojects/gst-libav/ext/libav/gstavcodecmap.c
+++ b/subprojects/gst-libav/ext/libav/gstavcodecmap.c
@@ -1049,6 +1049,12 @@ gst_ffmpeg_codecid_to_caps (enum AVCodecID codec_id,
           "parsed", G_TYPE_BOOLEAN, TRUE, NULL);
       break;
 
+    case AV_CODEC_ID_MXPEG:
+      caps =
+          gst_ff_vid_caps_new (context, NULL, codec_id, encode, "video/x-mxpeg",
+          NULL);
+      break;
+
     case AV_CODEC_ID_JPEG2000:
       caps =
           gst_ff_vid_caps_new (context, NULL, codec_id, encode, "image/x-j2c",