$NetBSD$

--- configure.orig	2011-05-31 22:11:47.000000000 +0000
+++ configure
@@ -10896,7 +10896,7 @@ fi
 # check for optimisation level
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking CFLAGS optimization level" >&5
 $as_echo_n "checking CFLAGS optimization level... " >&6; }
-if echo $CFLAGS | grep '.*-O[3s].*' >/dev/null 2>&1; then
+if echo $CFLAGS | grep '.*-O[3].*' >/dev/null 2>&1; then
     as_fn_error $? "maximum allowed optimization level is -O2" "$LINENO" 5
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: fine" >&5
