diff --git a/lib/roles/http/server/server.c b/lib/roles/http/server/server.c
index 781e5d4aa..38e03c8d0 100644
--- a/lib/roles/http/server/server.c
+++ b/lib/roles/http/server/server.c
@@ -1507,6 +1507,9 @@ lws_http_action(struct lws *wsi)
 		if (!n || n > 128)
 			goto bail_nuke_ah;
 
+		if (!lws_hdr_simple_ptr(wsi, WSI_TOKEN_HOST))
+			goto bail_nuke_ah;
+
 		p += lws_snprintf((char *)p, lws_ptr_diff(end, p), "https://");
 		memcpy(p, lws_hdr_simple_ptr(wsi, WSI_TOKEN_HOST), n);
 		p += n;