diff --git a/cmake/modules/FindCg.cmake b/cmake/modules/FindCg.cmake
index 3fdfe757ca..f7c43884a2 100644
--- a/cmake/modules/FindCg.cmake
+++ b/cmake/modules/FindCg.cmake
@@ -141,7 +141,7 @@ if(NOT CG_LIBRARY_DIR OR NOT CG_INCLUDE_DIRS)
     set(CG_LIBRARY_DIR "${CG_LIBRARY_DIR}" CACHE PATH "The path to NvidiaCG's library directory.") # Library path
   endif()
 
-  string(REGEX REPLACE "/Cg$" "" CG_BASE_INCLUDE_DIR ${CG_INCLUDE_DIR})
+  string(REGEX REPLACE "/Cg$" "" CG_BASE_INCLUDE_DIR "${CG_INCLUDE_DIR}")
   set(CG_INCLUDE_DIRS ${CG_BASE_INCLUDE_DIR} ${CG_INCLUDE_DIR})
 
   mark_as_advanced(CG_INCLUDE_DIRS)