--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -271,7 +271,8 @@
     if (WIN32)
       set(MODULE_INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib")
     else (WIN32)
-      set(MODULE_INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib/lua/${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}")
+      set(MODULE_INSTALL_LIB_DIR "${CMAKE_INSTALL_PREFIX}/lib/lua/${LUA_VERSION_MAJOR}.${LUA_VERSION_MINOR}"
+        CACHE PATH "Installation directory for module")
     endif (WIN32)
   endif (BUILD_MODULE)
   if (BUILD_STATIC_LIBS)