--- Makefile.opt	2004-07-09 08:18:29.000000000 +0900
+++ Makefile	2007-03-27 02:29:01.000000000 +0900
@@ -30,7 +30,7 @@
 srcdir= .
 VPATH= $(srcdir)
 
-CFLAGS= -O -I$(srcdir)/include -DATOMIC_UNCOLLECTABLE -DNO_SIGNALS -DNO_EXECUTE_PERMISSION -DSILENT -DALL_INTERIOR_POINTERS
+CFLAGS= -I$(srcdir)/include -DATOMIC_UNCOLLECTABLE -DNO_SIGNALS -DNO_EXECUTE_PERMISSION -DSILENT -DALL_INTERIOR_POINTERS
 
 # To build the parallel collector on Linux, add to the above:
 # -DGC_LINUX_THREADS -DPARALLEL_MARK -DTHREAD_LOCAL_ALLOC