diff --git a/CONFIG.gnuCommon b/CONFIG.gnuCommon
index f054802..d59a420 100644
--- a/CONFIG.gnuCommon
+++ b/CONFIG.gnuCommon
@@ -27,16 +27,16 @@ GPROF_CFLAGS_YES = -pg
 CODE_CFLAGS = $(PROF_CFLAGS_$(PROFILE)) $(GPROF_CFLAGS_$(GPROF))
 WARN_CFLAGS_YES = -Wall
 WARN_CFLAGS_NO = -w
-OPT_CFLAGS_YES = -O3
-OPT_CFLAGS_NO = -g
+OPT_CFLAGS_YES = -O0 -g
+OPT_CFLAGS_NO = -g -O0

 PROF_CXXFLAGS_YES = -p
 GPROF_CXXFLAGS_YES = -pg
 CODE_CXXFLAGS = $(PROF_CXXFLAGS_$(PROFILE)) $(GPROF_CXXFLAGS_$(GPROF))
 WARN_CXXFLAGS_YES = -Wall
 WARN_CXXFLAGS_NO = -w
-OPT_CXXFLAGS_YES = -O3
-OPT_CXXFLAGS_NO = -g
+OPT_CXXFLAGS_YES = -O0 -g
+OPT_CXXFLAGS_NO = -g -O0

 CODE_LDFLAGS = $(PROF_CXXFLAGS_$(PROFILE)) $(GPROF_CXXFLAGS_$(GPROF))