diff --git a/Dockerfile b/Dockerfile
index 998387a..49429ba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -47,6 +47,8 @@ RUN uv pip install --index-strategy unsafe-best-match -r /app/HunyuanVideo-1.5/r
     && uv pip install --upgrade tencentcloud-sdk-python \
     && uv pip install sgl-kernel==0.3.18
 
+ENV PYTHONPATH="/app/HunyuanVideo-1.5:$PYTHONPATH"
+
 # Optional attention backends from Hunyuan docs.
 # Build with: --build-arg INSTALL_OPTIONAL_ATTENTION=1
 ARG INSTALL_OPTIONAL_ATTENTION=0