diff --git a/test/sslapitest.c b/test/sslapitest.c
index 914471d7861be..a6b979bceb5ff 100644
--- a/test/sslapitest.c
+++ b/test/sslapitest.c
@@ -12194,6 +12194,7 @@ static int npn_advert_cb(SSL *ssl, const unsigned char **out,
         return SSL_TLSEXT_ERR_OK;
 
     case 1:
+        *out = NULL;
         *outlen = 0;
         return SSL_TLSEXT_ERR_OK;