diff --git a/src/proto_htx.c b/src/proto_htx.c
index 7bae526..ec08fb6 100644
--- a/src/proto_htx.c
+++ b/src/proto_htx.c
@@ -1803,7 +1803,7 @@
 		ctx.blk = NULL;
 		while (http_find_header(htx, hdr, &ctx, 0)) {
 			if ((ctx.value.len >= 9 && word_match(ctx.value.ptr, ctx.value.len, "Negotiate", 9)) ||
-			    (ctx.value.len >= 4 && word_match(ctx.value.ptr, ctx.value.len, "NTLM", 4))) {
+			    (ctx.value.len >= 4 && !memcmp(ctx.value.ptr, "NTLM", 4))) {
 				sess->flags |= SESS_FL_PREFER_LAST;
 				srv_conn->flags |= CO_FL_PRIVATE;
 			}