diff --git a/libavformat/mux.c b/libavformat/mux.c
index 498eb2e61f..77e03ee5ba 100644
--- a/libavformat/mux.c
+++ b/libavformat/mux.c
@@ -674,7 +674,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
  */
 static int write_packet(AVFormatContext *s, AVPacket *pkt)
 {
-    int ret, did_split;
+    int ret;
     int64_t pts_backup, dts_backup;
 
     pts_backup = pkt->pts;
@@ -739,12 +739,6 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
         }
     }
 
-#if FF_API_LAVF_MERGE_SD
-FF_DISABLE_DEPRECATION_WARNINGS
-    did_split = av_packet_split_side_data(pkt);
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-
     if (!s->internal->header_written) {
         ret = s->internal->write_header_ret ? s->internal->write_header_ret : write_header_internal(s);
         if (ret < 0)
@@ -767,12 +761,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
     }
 
 fail:
-#if FF_API_LAVF_MERGE_SD
-FF_DISABLE_DEPRECATION_WARNINGS
-    if (did_split)
-        av_packet_merge_side_data(pkt);
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
 
     if (ret < 0) {
         pkt->pts = pts_backup;
@@ -869,16 +857,6 @@ static int do_packet_auto_bsf(AVFormatContext *s, AVPacket *pkt) {
         }
     }
 
-#if FF_API_LAVF_MERGE_SD
-FF_DISABLE_DEPRECATION_WARNINGS
-    if (st->internal->nb_bsfcs) {
-        ret = av_packet_split_side_data(pkt);
-        if (ret < 0)
-            av_log(s, AV_LOG_WARNING, "Failed to split side data before bitstream filter\n");
-    }
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-
     for (i = 0; i < st->internal->nb_bsfcs; i++) {
         AVBSFContext *ctx = st->internal->bsfcs[i];
         // TODO: when any bitstream filter requires flushing at EOF, we'll need to
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 1a7996c4fd..d89dd56357 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -1677,13 +1677,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
             }
             st->inject_global_side_data = 0;
         }
-
-#if FF_API_LAVF_MERGE_SD
-FF_DISABLE_DEPRECATION_WARNINGS
-        if (!(s->flags & AVFMT_FLAG_KEEP_SIDE_DATA))
-            av_packet_merge_side_data(pkt);
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
     }
 
     av_opt_get_dict_val(s, "metadata", AV_OPT_SEARCH_CHILDREN, &metadata);
diff --git a/libavformat/version.h b/libavformat/version.h
index c0cd7dd409..3bb1e489cf 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -76,9 +76,6 @@
 #ifndef FF_API_HLS_WRAP
 #define FF_API_HLS_WRAP                 (LIBAVFORMAT_VERSION_MAJOR < 59)
 #endif
-#ifndef FF_API_LAVF_MERGE_SD
-#define FF_API_LAVF_MERGE_SD            (LIBAVFORMAT_VERSION_MAJOR < 58)
-#endif
 #ifndef FF_API_LAVF_KEEPSIDE_FLAG
 #define FF_API_LAVF_KEEPSIDE_FLAG       (LIBAVFORMAT_VERSION_MAJOR < 59)
 #endif