diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index 5598cf8374..d127e517dc 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -128,6 +128,8 @@ typedef struct mkv_track {
     AVCodecParserContext *av_parser;
     AVCodecContext *av_parser_codec;
 
+    bool require_keyframes;
+
     /* stuff for realaudio braincancer */
     double ra_pts;              /* previous audio timestamp */
     uint32_t sub_packet_size;   ///< sub packet size, per stream
@@ -200,7 +202,7 @@ typedef struct mkv_demuxer {
 
     bool index_has_durations;
 
-    bool eof_warning;
+    bool eof_warning, keyframe_warning;
 
     struct block_info tmp_block;
 } mkv_demuxer_t;
@@ -1752,6 +1754,10 @@ static int demux_mkv_open_audio(demuxer_t *demuxer, mkv_track_t *track)
     if (sh_a->samplerate == 8000 && strcmp(codec, "ac3") == 0)
         track->default_duration = 0;
 
+    // Deal with some FFmpeg-produced garbage, and assume all audio codecs can
+    // start decoding from anywhere.
+    track->require_keyframes = true;
+
     sh_a->extradata = extradata;
     sh_a->extradata_size = extradata_len;
 
@@ -2474,6 +2480,15 @@ static int handle_block(demuxer_t *demuxer, struct block_info *block_info)
 
     current_pts = tc / 1e9 - track->codec_delay;
 
+    if (track->require_keyframes && !keyframe) {
+        keyframe = true;
+        if (!mkv_d->keyframe_warning) {
+            MP_WARN(demuxer, "This is a broken file! Packets with incorrect "
+                    "keyframe flag found. Enabling workaround.\n");
+            mkv_d->keyframe_warning = true;
+        }
+    }
+
     if (track->type == MATROSKA_TRACK_AUDIO) {
         if (mkv_d->a_skip_to_keyframe)
             use_this_block &= keyframe;