diff --git a/src/Makefile b/src/Makefile
index 2f737066..d6e23170 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -10,7 +10,7 @@ endif
 
 ifeq ($(debug),yes)
     CPPFLAGS += -DKAK_DEBUG
-    CXXFLAGS += -Og
+    CXXFLAGS += -O0
     suffix := .debug
 else
     ifeq ($(debug),no)