diff --git a/cmake/utils.cmake b/cmake/utils.cmake
index 6bebf05b481785edd2f59aa7028437ff164edeb5..9d23d6f1a3293f1488d3fc3fca44dc1db9919160 100644
--- a/cmake/utils.cmake
+++ b/cmake/utils.cmake
@@ -2,8 +2,8 @@ macro(add_compile_flags langs)
     foreach(_lang ${langs})
         string (REPLACE ";" " " _flags "${ARGN}")
         set ("CMAKE_${_lang}_FLAGS" "${CMAKE_${_lang}_FLAGS} ${_flags}")
-        unset (${_lang})
-        unset (${_flags})
+        unset (_lang)
+        unset (_flags)
     endforeach()
 endmacro(add_compile_flags)