diff --git a/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs b/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs
index 297073166e..d491e687c3 100644
--- a/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs
+++ b/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs
@@ -26,6 +26,7 @@ namespace Jellyfin.Model.Tests
         [InlineData("Chrome", "mp4-h264-ac3-aacDef-srt-2600k", PlayMethod.Transcode, TranscodeReason.SecondaryAudioNotSupported, "Remux", "HLS.mp4")] // #6450
         [InlineData("Chrome", "mp4-h264-ac3-aacExt-srt-2600k", PlayMethod.Transcode, TranscodeReason.AudioIsExternal, "DirectStream", "HLS.mp4")] // #6450
         [InlineData("Chrome", "mp4-h264-ac3-srt-2600k", PlayMethod.Transcode, TranscodeReason.AudioCodecNotSupported, "DirectStream", "HLS.mp4")] // #6450
+        [InlineData("Chrome", "mkv-h264-ac3-srt-2600k", PlayMethod.Transcode, TranscodeReason.ContainerNotSupported | TranscodeReason.AudioCodecNotSupported, "DirectStream", "HLS.mp4")] // #6450
         [InlineData("Chrome", "mp4-hevc-aac-srt-15200k", PlayMethod.DirectPlay)]
         [InlineData("Chrome", "mp4-hevc-ac3-aac-srt-15200k", PlayMethod.Transcode, TranscodeReason.AudioCodecNotSupported, "DirectStream", "HLS.mp4")]
         [InlineData("Chrome", "mp4-hevc-ac3-aacDef-srt-15200k", PlayMethod.Transcode, TranscodeReason.SecondaryAudioNotSupported, "Remux", "HLS.mp4")]
@@ -40,6 +41,7 @@ namespace Jellyfin.Model.Tests
         [InlineData("Firefox", "mp4-h264-ac3-aacDef-srt-2600k", PlayMethod.Transcode, TranscodeReason.SecondaryAudioNotSupported, "Remux", "HLS.mp4")] // #6450
         [InlineData("Firefox", "mp4-h264-ac3-aacExt-srt-2600k", PlayMethod.Transcode, TranscodeReason.AudioIsExternal, "DirectStream", "HLS.mp4")] // #6450
         [InlineData("Firefox", "mp4-h264-ac3-srt-2600k", PlayMethod.Transcode, TranscodeReason.AudioCodecNotSupported, "DirectStream", "HLS.mp4")] // #6450
+        [InlineData("Firefox", "mkv-h264-ac3-srt-2600k", PlayMethod.Transcode, TranscodeReason.ContainerNotSupported | TranscodeReason.AudioCodecNotSupported, "DirectStream", "HLS.mp4")] // #6450
         [InlineData("Firefox", "mp4-hevc-aac-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecNotSupported, "Transcode", "HLS.mp4")]
         [InlineData("Firefox", "mp4-hevc-ac3-aac-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecNotSupported | TranscodeReason.AudioCodecNotSupported, "Transcode", "HLS.mp4")]
         [InlineData("Firefox", "mp4-hevc-ac3-aacDef-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecNotSupported | TranscodeReason.SecondaryAudioNotSupported, "Transcode", "HLS.mp4")]
@@ -54,6 +56,7 @@ namespace Jellyfin.Model.Tests
         [InlineData("SafariNext", "mp4-h264-ac3-aacDef-srt-2600k", PlayMethod.DirectPlay)] // #6450
         [InlineData("SafariNext", "mp4-h264-ac3-aacExt-srt-2600k", PlayMethod.DirectPlay)] // #6450
         [InlineData("SafariNext", "mp4-h264-ac3-srt-2600k", PlayMethod.DirectPlay)] // #6450
+        [InlineData("SafariNext", "mkv-h264-ac3-srt-2600k", PlayMethod.Transcode, TranscodeReason.ContainerNotSupported | TranscodeReason.AudioChannelsNotSupported, "Remux", "HLS.mp4")] // #6450
         [InlineData("SafariNext", "mp4-hevc-aac-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecTagNotSupported, "Remux", "HLS.mp4")] // #6450
         [InlineData("SafariNext", "mp4-hevc-ac3-aac-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecTagNotSupported | TranscodeReason.AudioChannelsNotSupported, "DirectStream", "HLS.mp4")] // #6450
         [InlineData("SafariNext", "mp4-hevc-ac3-aacExt-srt-15200k", PlayMethod.Transcode, TranscodeReason.VideoCodecTagNotSupported | TranscodeReason.AudioChannelsNotSupported, "DirectStream", "HLS.mp4")] // #6450
diff --git a/tests/Jellyfin.Model.Tests/Test Data/MediaSourceInfo-mkv-h264-ac3-srt-2600k.json b/tests/Jellyfin.Model.Tests/Test Data/MediaSourceInfo-mkv-h264-ac3-srt-2600k.json
new file mode 100644
index 0000000000..4f6d5bf000
--- /dev/null
+++ b/tests/Jellyfin.Model.Tests/Test Data/MediaSourceInfo-mkv-h264-ac3-srt-2600k.json	
@@ -0,0 +1,71 @@
+{
+    "Id": "a766d122b58e45d9492d17af77748bf5",
+    "Path": "/Media/MyVideo-720p.mkv",
+    "Container": "mkv",
+    "Size": 835317696,
+    "Name": "MyVideo-720p",
+    "ETag": "579a34c6d5dfb21d81539a51220b6a23",
+    "RunTimeTicks": 25801230336,
+    "SupportsTranscoding": true,
+    "SupportsDirectStream": true,
+    "SupportsDirectPlay": true,
+    "SupportsProbing": true,
+    "MediaStreams": [
+        {
+            "Codec": "h264",
+            "CodecTag": "avc1",
+            "Language": "eng",
+            "TimeBase": "1/11988",
+            "VideoRange": "SDR",
+            "DisplayTitle": "720p H264 SDR",
+            "NalLengthSize": "0",
+            "BitRate": 2032876,
+            "BitDepth": 8,
+            "RefFrames": 1,
+            "IsDefault": true,
+            "Height": 720,
+            "Width": 1280,
+            "AverageFrameRate": 23.976,
+            "RealFrameRate": 23.976,
+            "Profile": "High",
+            "Type": 1,
+            "AspectRatio": "16:9",
+            "PixelFormat": "yuv420p",
+            "Level": 41
+        },
+        {
+            "Codec": "ac3",
+            "CodecTag": "ac-3",
+            "Language": "eng",
+            "TimeBase": "1/48000",
+            "DisplayTitle": "En - Dolby Digital - 5.1 - Default",
+            "ChannelLayout": "5.1",
+            "BitRate": 384000,
+            "Channels": 6,
+            "SampleRate": 48000,
+            "IsDefault": true,
+            "Index": 1,
+            "Score": 202
+        },
+        {
+            "Codec": "srt",
+            "Language": "eng",
+            "TimeBase": "1/1000000",
+            "localizedUndefined": "Undefined",
+            "localizedDefault": "Default",
+            "localizedForced": "Forced",
+            "DisplayTitle": "En - Default",
+            "BitRate": 92,
+            "IsDefault": true,
+            "Type": 2,
+            "Index": 2,
+            "Score": 6421,
+            "IsExternal": true,
+            "IsTextSubtitleStream": true,
+            "SupportsExternalStream": true
+        }
+    ],
+    "Bitrate": 2590008,
+    "DefaultAudioStreamIndex": 1,
+    "DefaultSubtitleStreamIndex": 2
+}