diff --git a/src/Makefile b/src/Makefile
index 463afccc..f43e3c24 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -372,7 +372,7 @@ else
 
 	# build a normal optimised version
 	WINDRESFLAGS = -DNDEBUG
-	#CFLAGS+=-O2
+	CFLAGS+=-O3
 endif
 	CFLAGS+=-g $(OPTS) $(M5) $(WINDRESFLAGS)