diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index ddbb78a199..b70bce68ad 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -222,6 +222,7 @@ void dtls1_free(SSL *s)
 	pqueue_free(s->d1->buffered_app_data.q);
 
 	OPENSSL_free(s->d1);
+	s->d1 = NULL;
 	}
 
 void dtls1_clear(SSL *s)