diff --git a/cmake/python.cmake b/cmake/python.cmake
index 8d65c62409..ae279a0824 100644
--- a/cmake/python.cmake
+++ b/cmake/python.cmake
@@ -290,7 +290,7 @@ if(BUILD_TESTING)
   add_custom_command(TARGET python_package POST_BUILD
     # Clean previous install otherwise pip install may do nothing
     COMMAND ${CMAKE_COMMAND} -E remove_directory ${VENV_DIR}
-    COMMAND ${VENV_EXECUTABLE} -p ${Python3_EXECUTABLE} ${VENV_DIR}
+    COMMAND ${VENV_EXECUTABLE} -p ${Python3_EXECUTABLE} --system-site-packages ${VENV_DIR}
     #COMMAND ${VENV_EXECUTABLE} ${VENV_DIR}
     # Must NOT call it in a folder containing the setup.py otherwise pip call it
     # (i.e. "python setup.py bdist") while we want to consume the wheel package
diff --git a/makefiles/Makefile.python.mk b/makefiles/Makefile.python.mk
index 621e5efeb4..28a3867b88 100644
--- a/makefiles/Makefile.python.mk
+++ b/makefiles/Makefile.python.mk
@@ -1038,7 +1038,7 @@ endif
 .PHONY: test_package_python # Test Python "ortools" wheel package
 test_package_python: package_python
 	-$(DELREC) $(PYPI_ARCHIVE_TEMP_DIR)$Svenv
-	$(PYTHON_EXECUTABLE) -m venv $(PYPI_ARCHIVE_TEMP_DIR)$Svenv
+	$(PYTHON_EXECUTABLE) -m venv --system-site-packages $(PYPI_ARCHIVE_TEMP_DIR)$Svenv
 	$(COPY) test.py.in $(PYPI_ARCHIVE_TEMP_DIR)$Svenv$Stest.py
 	$(COPY) ortools$Salgorithms$Ssamples$Ssimple_knapsack_program.py $(PYPI_ARCHIVE_TEMP_DIR)$Svenv
 	$(COPY) ortools$Sgraph$Ssamples$Ssimple_max_flow_program.py $(PYPI_ARCHIVE_TEMP_DIR)$Svenv