diff --git a/Makefile.rules b/Makefile.rules
index 688a4853cc88c53df1e268678f85c3305361495b..35f522ed026b55e11a5807435b9f59abc9a64766 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -35,7 +35,7 @@ else
     CMD_PREFIX=
 endif
 
-OPTIMIZE?=-O6
+OPTIMIZE?=-O3
 ifneq ($(findstring darwin,$(OSARCH)),)
   ifeq ($(shell if test `/usr/bin/sw_vers -productVersion | cut -c4` -gt 5; then echo 6; else echo 0; fi),6)
     # Snow Leopard/Lion has an issue with this optimization flag on large files (like chan_sip)