diff --git a/cmake/CheckIncludeFiles.cmake b/cmake/CheckIncludeFiles.cmake
index 998cd18a4..c7fc2b5de 100644
--- a/cmake/CheckIncludeFiles.cmake
+++ b/cmake/CheckIncludeFiles.cmake
@@ -56,9 +56,9 @@ macro(CHECK_INCLUDE_FILES INCLUDE VARIABLE)
     endif()
 
     if(_lang STREQUAL "C")
-      set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${var}.c)
+      set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${VARIABLE}.c)
     elseif(_lang STREQUAL "CXX")
-      set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${var}.cpp)
+      set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckIncludeFiles/${VARIABLE}.cpp)
     else()
       message(FATAL_ERROR "Unknown language:\n  ${_lang}\nSupported languages: C, CXX.\n")
     endif()