diff --git a/subprojects/gst-plugins-good/docs/gst_plugins_cache.json b/subprojects/gst-plugins-good/docs/gst_plugins_cache.json
index 58c41516de..5fbadaa1f7 100644
--- a/subprojects/gst-plugins-good/docs/gst_plugins_cache.json
+++ b/subprojects/gst-plugins-good/docs/gst_plugins_cache.json
@@ -19799,6 +19799,74 @@
                     }
                 ]
             },
+            "GstRTPMux": {
+                "hierarchy": [
+                    "GstRTPMux",
+                    "GstElement",
+                    "GstObject",
+                    "GInitiallyUnowned",
+                    "GObject"
+                ],
+                "kind": "object",
+                "properties": {
+                    "seqnum": {
+                        "blurb": "The RTP sequence number of the last processed packet",
+                        "conditionally-available": false,
+                        "construct": false,
+                        "construct-only": false,
+                        "controllable": false,
+                        "default": "0",
+                        "max": "-1",
+                        "min": "0",
+                        "mutable": "null",
+                        "readable": true,
+                        "type": "guint",
+                        "writable": false
+                    },
+                    "seqnum-offset": {
+                        "blurb": "Offset to add to all outgoing seqnum (-1 = random)",
+                        "conditionally-available": false,
+                        "construct": false,
+                        "construct-only": false,
+                        "controllable": false,
+                        "default": "-1",
+                        "max": "2147483647",
+                        "min": "-1",
+                        "mutable": "null",
+                        "readable": true,
+                        "type": "gint",
+                        "writable": true
+                    },
+                    "ssrc": {
+                        "blurb": "The SSRC of the packets (default == random)",
+                        "conditionally-available": false,
+                        "construct": false,
+                        "construct-only": false,
+                        "controllable": false,
+                        "default": "-1",
+                        "max": "-1",
+                        "min": "0",
+                        "mutable": "playing",
+                        "readable": true,
+                        "type": "guint",
+                        "writable": true
+                    },
+                    "timestamp-offset": {
+                        "blurb": "Offset to add to all outgoing timestamps (-1 = random)",
+                        "conditionally-available": false,
+                        "construct": false,
+                        "construct-only": false,
+                        "controllable": false,
+                        "default": "-1",
+                        "max": "2147483647",
+                        "min": "-1",
+                        "mutable": "null",
+                        "readable": true,
+                        "type": "gint",
+                        "writable": true
+                    }
+                }
+            },
             "GstRtpNtpTimeSource": {
                 "kind": "enum",
                 "values": [
diff --git a/subprojects/gst-plugins-good/gst/rtpmanager/gstrtpmux.c b/subprojects/gst-plugins-good/gst/rtpmanager/gstrtpmux.c
index 5de47ae34e..a5ad2306cb 100644
--- a/subprojects/gst-plugins-good/gst/rtpmanager/gstrtpmux.c
+++ b/subprojects/gst-plugins-good/gst/rtpmanager/gstrtpmux.c
@@ -164,6 +164,8 @@ gst_rtp_mux_class_init (GstRTPMuxClass * klass)
       GST_DEBUG_FUNCPTR (gst_rtp_mux_request_new_pad);
   gstelement_class->release_pad = GST_DEBUG_FUNCPTR (gst_rtp_mux_release_pad);
   gstelement_class->change_state = GST_DEBUG_FUNCPTR (gst_rtp_mux_change_state);
+
+  gst_type_mark_as_plugin_api (GST_TYPE_RTP_MUX, 0);
 }
 
 static void