diff --git a/make/defs.mk b/make/defs.mk
index cb7c94a0..a24e3496 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -265,7 +265,7 @@ ifeq ($(USE_COMPILER_DEBUG_OPTS),true)
 	PROJECT_LDFLAGS     += -Wall -g3
 else
 	ifeq ($(USE_COMPILER_OPTIMIZATION_OPTS),true)
-		PROJECT_CFLAGS   += -funroll-loops -O2 -NDEBUG
+		PROJECT_CFLAGS   += -funroll-loops -O2 -DNDEBUG
 	endif
 endif