diff --git a/mk/cc.defs b/mk/cc.defs
index 8560bea..2641aae 100644
--- a/mk/cc.defs
+++ b/mk/cc.defs
@@ -241,7 +241,6 @@ LD_LIBS += \
 #---------------------------------------------------------------------------------------- CMake
 
 export CMAKE_CC_FLAGS=\
-	-UNDEBUG \
 	$(CC_FLAGS.core)
 
 export CMAKE_CC_C_FLAGS=$(CC_C_FLAGS)