diff --git a/bin/ffx.py b/bin/ffx.py
index 8f31218..31cb224 100755
--- a/bin/ffx.py
+++ b/bin/ffx.py
@@ -169,6 +169,8 @@ for aStream in audioStreams:
         if channels == 6:
             audioTokens += [f"-c:a:{audioStreamIndex}",
                             'libopus',
+                            f"-filter:a:{audioStreamIndex}",
+                            "channelmap=FL-FL|FR-FR|FC-FC|LFE-LFE|SL-BL|SR-BR:5.1",
                             f"-b:a:{audioStreamIndex}",
                             ac3Bandwidth]