diff --git a/modules/core/m_server.c b/modules/core/m_server.c
index a86ac573f..b9ae59c03 100644
--- a/modules/core/m_server.c
+++ b/modules/core/m_server.c
@@ -76,6 +76,7 @@ mr_server(struct Client *client_p, struct Client *source_p, int parc, const char
 	struct Client *target_p;
 	int hop;
 	unsigned int required_mask;
+	const char *missing;
 
 	name = parv[1];
 	hop = atoi(parv[2]);
@@ -194,15 +195,22 @@ mr_server(struct Client *client_p, struct Client *source_p, int parc, const char
 	}
 
 	/* check to ensure any "required" caps are set. --nenolod */
-	/* XXX: show required CAPABs. */
 	required_mask = capability_index_get_required(serv_capindex);
 	if (!IsCapable(client_p, required_mask))
 	{
+		missing = capability_index_list(serv_capindex, required_mask &
+				~client_p->localClient->caps);
 		sendto_realops_snomask(SNO_GENERAL, is_remote_connect(client_p) ? L_NETWIDE : L_ALL,
-					"Link %s dropped, required CAPABs are missing", name);
-		ilog(L_SERVER, "Link %s%s dropped, required CAPABs are missing",
+					"Link %s dropped, required CAPABs [%s] are missing",
+					name, missing);
+		ilog(L_SERVER, "Link %s%s dropped, required CAPABs [%s] are missing",
 				EmptyString(client_p->name) ? name : "",
-				log_client_name(client_p, SHOW_IP));
+				log_client_name(client_p, SHOW_IP), missing);
+		/* Do not use '[' in the below message because it would cause
+		 * it to be considered potentially unsafe (might disclose IP
+		 * addresses)
+		 */
+		sendto_one(client_p, "ERROR :Missing required CAPABs (%s)", missing);
 		exit_client(client_p, client_p, client_p, "Missing required CAPABs");
 
 		return 0;