diff --git a/Makefile b/Makefile
index e08cfc5c1..72b351346 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,3 @@
-ABC_PYTHON=/usr/bin/python
-READLINE=0
 
 CC   := gcc
 CXX  := g++
@@ -42,7 +40,7 @@ arch_flags : arch_flags.c
 	$(CC) arch_flags.c -o arch_flags
 
 ARCHFLAGS ?= $(shell $(CC) arch_flags.c -o arch_flags && ./arch_flags)
-OPTFLAGS  ?= -g -O3 #-DABC_NAMESPACE=xxx
+OPTFLAGS  ?= -g -O #-DABC_NAMESPACE=xxx
 MSG_PREFIX ?=
 
 CFLAGS   += -Wall -Wno-unused-function -Wno-write-strings -Wno-sign-compare $(OPTFLAGS) $(ARCHFLAGS) -Isrc