diff --git a/makefile b/makefile
index 503c030..4146ba2 100644
--- a/makefile
+++ b/makefile
@@ -3,7 +3,7 @@
 # To regenerate run ``niminst csource`` or ``koch csource``
 
 CC ?= gcc
-CFLAGS += -Ic_code -w -O3 -fno-strict-aliasing
+CFLAGS += -Ic_code -w -fno-strict-aliasing
 LDFLAGS +=
 binDir = bin