diff --git a/include/build_config/SDL_build_config.h.cmake b/include/build_config/SDL_build_config.h.cmake
index 2b1bdcda4c..2d64c74b1d 100644
--- a/include/build_config/SDL_build_config.h.cmake
+++ b/include/build_config/SDL_build_config.h.cmake
@@ -228,8 +228,9 @@
 #cmakedefine USE_POSIX_SPAWN @USE_POSIX_SPAWN@
 
 /* SDL internal assertion support */
-#if @SDL_DEFAULT_ASSERT_LEVEL_CONFIGURED@
-#cmakedefine SDL_DEFAULT_ASSERT_LEVEL @SDL_DEFAULT_ASSERT_LEVEL@
+#cmakedefine SDL_DEFAULT_ASSERT_LEVEL_CONFIGURED 1
+#ifdef SDL_DEFAULT_ASSERT_LEVEL_CONFIGURED
+#define SDL_DEFAULT_ASSERT_LEVEL @SDL_DEFAULT_ASSERT_LEVEL@
 #endif
 
 /* Allow disabling of major subsystems */