diff --git a/.make.defaults b/.make.defaults
index 151afab4e..a243adc07 100644
--- a/.make.defaults
+++ b/.make.defaults
@@ -331,6 +331,9 @@ __check_defined = \
 	$(MAKE) PIP_TARGET=data-prep-toolkit-spark .defaults.pip-uninstall;	\
 	$(MAKE) PYTHON_PROJECT_DIR=$(DPK_PYTHON_LIB_DIR) .defaults.install-src-venv;	\
 	$(MAKE) PYTHON_PROJECT_DIR=$(DPK_SPARK_LIB_DIR) .defaults.install-src-venv;	\
+	if [ -d ../python ]; then                                               \
+		$(MAKE) PYTHON_PROJECT_DIR=../python .defaults.install-src-venv;    \
+	fi
 	echo Installed source from Spark processing library for `which $(PYTHON)`
 
 # Run tests in test directory from that dir after adding ../src to PYTHONPATH