--- a/python/CMakeLists.txt	2020-02-19 12:25:07.000000000 +0000
+++ b/python/CMakeLists.txt	2020-02-20 14:56:26.810463000 +0000
@@ -22,7 +22,9 @@
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/docs/Makefile.in ${CMAKE_CURRENT_SOURCE_DIR}/docs/Makefile)
 	add_custom_target(pyapi ALL COMMAND ${PYTHON} ${SETUP_PY} build -b ${PYAPI_BUILD_DIR} ${DEBUG})
 	add_custom_target(pyapidoc COMMAND make -f ${CMAKE_CURRENT_SOURCE_DIR}/docs/Makefile html)
-    execute_process(COMMAND ${PYTHON} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib(plat_specific=True))"
-        OUTPUT_VARIABLE PYTHON_MODULE_PATH OUTPUT_STRIP_TRAILING_WHITESPACE)
+    if(NOT DEFINED PYTHON_MODULE_PATH)
+        execute_process(COMMAND ${PYTHON} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib(plat_specific=True))"
+            OUTPUT_VARIABLE PYTHON_MODULE_PATH OUTPUT_STRIP_TRAILING_WHITESPACE)
+    endif()
     install(CODE "execute_process(COMMAND ${PYTHON} ${SETUP_PY} build -b ${PYAPI_BUILD_DIR} install --install-lib=\$ENV{DESTDIR}/${PYTHON_MODULE_PATH})")
 endif()