diff --git a/backend/python/liquid-audio/requirements-mps.txt b/backend/python/liquid-audio/requirements-mps.txt
index f57687f29..3c9c36cca 100644
--- a/backend/python/liquid-audio/requirements-mps.txt
+++ b/backend/python/liquid-audio/requirements-mps.txt
@@ -1,3 +1,4 @@
+# MPS (Apple Silicon / Metal) build profile - installed by the darwin CI job.
 torch>=2.8.0
 torchaudio>=2.8.0
 torchcodec>=0.9.1