diff --git a/mk/spdk.common.mk b/mk/spdk.common.mk
index f44ba29aa..26860c3dc 100644
--- a/mk/spdk.common.mk
+++ b/mk/spdk.common.mk
@@ -53,7 +53,7 @@ endif
 ifeq ($(CONFIG_DEBUG), y)
 COMMON_CFLAGS += -DDEBUG -O0
 else
-COMMON_CFLAGS += -O2
+COMMON_CFLAGS += -DNDEBUG -O2
 endif
 
 CFLAGS   += $(COMMON_CFLAGS) -Wno-pointer-sign -std=gnu11