diff --git a/CMakeLists.txt b/CMakeLists.txt
index d3a77ab2..d0a06a3a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -194,7 +194,7 @@ if (USE_PYTHON)
     add_definitions(-DNG_PYTHON)
 
     include_directories(${PYBIND_INCLUDE_DIR})
-    include_directories(${PYTHON_INCLUDE_DIR})
+    include_directories(${PYTHON_INCLUDE_DIRS})
 
     install(DIRECTORY ${PYBIND_INCLUDE_DIR}/pybind11 DESTINATION include COMPONENT netgen_devel)
     install(FILES ${PYBIND_INCLUDE_DIR}/../LICENSE DESTINATION include/pybind11 COMPONENT netgen_devel)