diff --git a/.gitea/workflows/build.yml b/.gitea/workflows/build.yml
index 71c1c71..9f62a15 100644
--- a/.gitea/workflows/build.yml
+++ b/.gitea/workflows/build.yml
@@ -31,3 +31,5 @@ jobs:
           tags: |
             git.sdgarren.com/scott/rocm-chatterbox-whisper:latest
             git.sdgarren.com/scott/rocm-chatterbox-whisper:${{ gitea.sha }}
+          cache-from: type=registry,ref=git.sdgarren.com/scott/rocm-chatterbox-whisper:buildcache
+          cache-to: type=registry,ref=git.sdgarren.com/scott/rocm-chatterbox-whisper:buildcache,mode=max
diff --git a/Dockerfile.rocm b/Dockerfile.rocm
index ef9a626..f94cc54 100644
--- a/Dockerfile.rocm
+++ b/Dockerfile.rocm
@@ -17,8 +17,6 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 WORKDIR /app
 
-COPY perth_stub.py .
-
 # Step 1: Install ROCm-compatible PyTorch stack first.
 # This must happen before anything else to prevent pip from pulling CPU wheels.
 COPY requirements-rocm-init.txt .
@@ -32,7 +30,8 @@ RUN pip3 install -r requirements-rocm.txt
 RUN pip3 install --no-deps chatterbox-tts
 
 # Stub out resemble-perth (audio watermarking, unnecessary for self-hosted use).
-# Install as 'perth' module to satisfy chatterbox's import.
+# Placed after pip layers so changes to the stub don't bust the cache above.
+COPY perth_stub.py .
 RUN python3 -c "import site; print(site.getsitepackages()[0])" | \
     xargs -I{} cp /app/perth_stub.py {}/perth.py