diff --git a/cmake/Modules/UseOptimization.cmake b/cmake/Modules/UseOptimization.cmake
index 7a09605dd..7156e32e8 100644
--- a/cmake/Modules/UseOptimization.cmake
+++ b/cmake/Modules/UseOptimization.cmake
@@ -64,8 +64,8 @@ if (CXX_COMPAT_GCC)
   # use these options for release builds - full optimization
   add_options (ALL_LANGUAGES "${_prof_RELEASE}" ${_opt_rel} ${_opt_flags})
   option(WITH_NDEBUG "Disable asserts in release mode" ON)
-  if(WITH_NDEBUG)
-    add_options (ALL_LANGUAGES "${_prof_RELEASE}" -DNDEBUG)
+  if(NOT WITH_NDEBUG)
+    add_options (ALL_LANGUAGES "${_prof_RELEASE}" -UNDEBUG)
   endif()
 
 else ()