diff --git a/encode.py b/encode.py
index 57aabcd..a2cc8cd 100755
--- a/encode.py
+++ b/encode.py
@@ -50,6 +50,7 @@ def encode_episode(podcast, episode, format):
         if format == "m4a":
             command.extend(["-c:a", "libfdk_aac"])
         command.extend(["-c:v", "copy"])
+        command.extend(["-bitexact"])  # deterministic output
         command.extend(options)
         for k, v in tags.items():
             command.extend(["-metadata", f"{k}={v}"])