1 files changed, 2 insertions, 2 deletions

diff --git a/src/openssl.c b/src/openssl.c
index f9ff4d5..562927d 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -4544,8 +4544,8 @@ static int sx_setAlpnProtos(lua_State *L) {
         }
 done:
         luaL_pushresult(&B);
-
-        if (0 != SSL_CTX_set_alpn_protos(ctx, (const unsigned char*)lua_tostring(L, -1), protos_len)) {
+        tmp = lua_tolstring(L, -1, &len);
+        if (0 != SSL_CTX_set_alpn_protos(ctx, (const unsigned char*)tmp, len)) {
                 lua_pushnil(L);
                 return 1;
         }