diff --git a/Makefile b/Makefile
index d6c645f0f33676d1e1a3372f1266a62f646a94b6..b41a820275f45a589e018dd653cbeee9f2e09a52 100644
--- a/Makefile
+++ b/Makefile
@@ -22,8 +22,15 @@ makefiles = \
   doc/manual/local.mk \
   tests/local.mk
 
-GLOBAL_CXXFLAGS += -std=c++0x
+GLOBAL_CXXFLAGS += -std=c++0x -g -Wall
 
 include Makefile.config
 
+OPTIMIZE = 1
+
+ifeq ($(OPTIMIZE), 1)
+  GLOBAL_CFLAGS += -O3
+  GLOBAL_CXXFLAGS += -O3
+endif
+
 include mk/lib.mk
diff --git a/configure.ac b/configure.ac
index 00c1d495d445fd1d31d3f9d4c40efd0613dac2ad..89fd6b96e79d1b8f41fc5d8786b29aa9c4df77af 100644
--- a/configure.ac
+++ b/configure.ac
@@ -54,8 +54,8 @@ if test "$sys_name" = sunos; then
 fi
 
 
-CFLAGS=${CFLAGS:--g -O3 -Wall}
-CXXFLAGS=${CXXFLAGS:--g -O3 -Wall}
+CFLAGS=
+CXXFLAGS=
 AC_PROG_CC
 AC_PROG_CXX