diff --git a/libavcodec/cbs_h264.h b/libavcodec/cbs_h264.h
index b39e7480c9..9f7c2a0d30 100644
--- a/libavcodec/cbs_h264.h
+++ b/libavcodec/cbs_h264.h
@@ -468,10 +468,13 @@ typedef struct CodedBitstreamH264Context {
 
 /**
  * Add an SEI message to an access unit.
+ *
+ * On success, the payload will be owned by a unit in access_unit;
+ * on failure, the content of the payload will be freed.
  */
 int ff_cbs_h264_add_sei_message(CodedBitstreamContext *ctx,
                                 CodedBitstreamFragment *access_unit,
-                                const H264RawSEIPayload *payload);
+                                H264RawSEIPayload *payload);
 
 /**
  * Delete an SEI message from an access unit.
diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 8da8421e47..2dc261f7a5 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -1586,7 +1586,7 @@ const CodedBitstreamType ff_cbs_type_h265 = {
 
 int ff_cbs_h264_add_sei_message(CodedBitstreamContext *ctx,
                                 CodedBitstreamFragment *au,
-                                const H264RawSEIPayload *payload)
+                                H264RawSEIPayload *payload)
 {
     H264RawSEI *sei = NULL;
     int err, i;
@@ -1608,8 +1608,10 @@ int ff_cbs_h264_add_sei_message(CodedBitstreamContext *ctx,
         AVBufferRef *sei_ref;
 
         sei = av_mallocz(sizeof(*sei));
-        if (!sei)
-            return AVERROR(ENOMEM);
+        if (!sei) {
+            err = AVERROR(ENOMEM);
+            goto fail;
+        }
 
         sei->nal_unit_header.nal_unit_type = H264_NAL_SEI;
         sei->nal_unit_header.nal_ref_idc   = 0;
@@ -1618,7 +1620,8 @@ int ff_cbs_h264_add_sei_message(CodedBitstreamContext *ctx,
                                    &cbs_h264_free_sei, NULL, 0);
         if (!sei_ref) {
             av_freep(&sei);
-            return AVERROR(ENOMEM);
+            err = AVERROR(ENOMEM);
+            goto fail;
         }
 
         for (i = 0; i < au->nb_units; i++) {
@@ -1631,13 +1634,16 @@ int ff_cbs_h264_add_sei_message(CodedBitstreamContext *ctx,
                                          sei, sei_ref);
         av_buffer_unref(&sei_ref);
         if (err < 0)
-            return err;
+            goto fail;
     }
 
     memcpy(&sei->payload[sei->payload_count], payload, sizeof(*payload));
     ++sei->payload_count;
 
     return 0;
+fail:
+    cbs_h264_free_sei_payload(payload);
+    return err;
 }
 
 void ff_cbs_h264_delete_sei_message(CodedBitstreamContext *ctx,