--- a/configure.in
+++ b/configure.in
@@ -51,7 +51,7 @@
 	fi
 	])
 
-CFLAGS="$OPTFLAGS $MPIFLAGS  -Wall -Werror $MACFLAG"
+CFLAGS="$CFLAGS $OPTFLAGS $MPIFLAGS -Wall $MACFLAG"
 
 AC_PROG_CC([$COMP_LIST])