diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0ce05ea..1e8c4ed 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -34,18 +34,11 @@ if(NOT DEFINED CMAKE_INSTALL_CMAKEDIR)
     set(CMAKE_INSTALL_CMAKEDIR "${CMAKE_INSTALL_LIBDIR}/cmake/nanopb")
 endif()
 
-execute_process(
-    COMMAND ${Python_EXECUTABLE} -c
-        "import os.path, sys, sysconfig; print(os.path.relpath(sysconfig.get_path('purelib'), start=sys.prefix))"
-    OUTPUT_VARIABLE PYTHON_INSTDIR
-    OUTPUT_STRIP_TRAILING_WHITESPACE
-)
-
 if(nanopb_BUILD_GENERATOR)
     set(generator_protos nanopb)
-    if(NOT DEFINED nanopb_PROTOC_PATH)
-        message(FATAL_ERROR "nanopb_PROTOC_PATH not defined")
-    endif()
+    if(NOT DEFINED nanopb_PROTOC_PATH)
+        message(FATAL_ERROR "nanopb_PROTOC_PATH not defined")
+    endif()
     foreach(generator_proto IN LISTS generator_protos)
         string(REGEX REPLACE "([^;]+)" "${PROJECT_SOURCE_DIR}/generator/proto/\\1.proto" generator_proto_file "${generator_proto}")
         string(REGEX REPLACE "([^;]+)" "\\1_pb2.py" generator_proto_py_file "${generator_proto}")
@@ -58,12 +51,12 @@ if(nanopb_BUILD_GENERATOR)
         install(
             FILES ${PROJECT_BINARY_DIR}/${generator_proto_py_file}
                   ${generator_proto_file}
-            DESTINATION ${PYTHON_INSTDIR}/proto/
+            DESTINATION ${CMAKE_INSTALL_DATADIR}/proto/
         )
     endforeach()
 
     install( FILES generator/proto/_utils.py
-             DESTINATION ${PYTHON_INSTDIR}/proto/ )
+             DESTINATION ${CMAKE_INSTALL_DATADIR}/proto/ )
 endif()
 
 if(WIN32)