diff --git a/src/Make.conf b/src/Make.conf
index 8924d7e1493..02268ce2d48 100644
--- a/src/Make.conf
+++ b/src/Make.conf
@@ -4,7 +4,7 @@
 
 CC=quietgcc
 LD=quietgcc
-CFLAGS=-ggdb -I$(GOROOT)/include -O1 -fno-inline
+CFLAGS=-ggdb -I$(GOROOT)/include -O2 -fno-inline
 O=o
 YFLAGS=-d
 # GNU Make syntax: