diff --git a/makefile b/makefile
index 855c358..54a9d59 100644
--- a/makefile
+++ b/makefile
@@ -3,7 +3,7 @@
 # To regenerate run ``niminst csource`` or ``koch csource``
 
 CC ?= gcc
-CFLAGS += -Ic_code -w -fmax-errors=3 -O3 -fno-strict-aliasing -fno-ident -fno-math-errno 
+CFLAGS += -Ic_code -w -fmax-errors=3 -fno-strict-aliasing -fno-ident -fno-math-errno 
 LDFLAGS += 
 binDir = bin