$OpenBSD: patch-lib_tools_c_src_Makefile_in,v 1.5 2012/05/26 09:08:57 jasper Exp $
--- lib/tools/c_src/Makefile.in.orig	Sun Apr  1 20:15:00 2012
+++ lib/tools/c_src/Makefile.in	Tue May 22 09:22:15 2012
@@ -109,7 +109,7 @@ EMEM_INCLUDES =	-I$(ERL_TOP)/erts/include \
 EMEM_HEADERS = erl_memory_trace_block_table.h
 EMEM_SRCS = erl_memory.c erl_memory_trace_block_table.c
 
-EMEM_CFLAGS = $(THR_DEFS) $(subst O2,O3, $(CFLAGS)) $(EMEM_INCLUDES)
+EMEM_CFLAGS = $(THR_DEFS) $(CFLAGS) $(EMEM_INCLUDES)
 EMEM_LDFLAGS = $(LDFLAGS)
 
 ifeq ($(USING_VC), yes)
