diff --git a/tools/autoplay-batch.sh b/tools/autoplay-batch.sh
index bc713cee..0b5d37a9 100755
--- a/tools/autoplay-batch.sh
+++ b/tools/autoplay-batch.sh
@@ -106,10 +106,9 @@ fi
 # Flatpak's sandboxed Godot resolves AUTO_PLAY_DIR against an unspecified CWD,
 # not the caller's shell CWD — a relative path silently produces 0-byte
 # meta.json / turn_stats.jsonl even when the game itself completes (game.log
-# is fine because it's redirected host-side). realpath -m tolerates the path
-# not existing yet; it will be mkdir'd just below. Also ensures the /tmp
-# reject check that follows catches all forms (./tmp, ../tmp, etc).
-RESULTS_DIR="$(realpath -m "$RESULTS_DIR")"
+# is fine because it's redirected host-side). Use python realpath (portable
+# across macOS BSD + linux GNU; tolerates non-existing path like realpath -m).
+RESULTS_DIR="$(python3 -c 'import os,sys; print(os.path.realpath(sys.argv[1]))' "$RESULTS_DIR")"
 
 # Flatpak sandbox can't write to /tmp. Reject /tmp paths outright instead of
 # silently redirecting — persistent output belongs under the repo.