diff --git a/Makefile.conf b/Makefile.conf
index 126cc86..fd2e625 100644
--- a/Makefile.conf
+++ b/Makefile.conf
@@ -5,6 +5,7 @@ BUILD_DIR = ./build
 DIST_DIR = ./dist
 VERSION_FILE = ./src/pEp/__version__.py
 BUILD_INPLACE = ./src/pEp/_pEp.cpython-38-darwin.so
+BUILD_INPLACE += ./src/pEp/_gen.cpython-38-darwin.so
 PYTHON_ARTIFACTS += ./.eggs
 PYTHON_ARTIFACTS += ./src/pEp.egg-info
 PYTHON_ARTIFACTS += ./.pytest_cache