diff --git a/src/tools.c b/src/tools.c
index 79d1d5c9b..4ecbdc4d7 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -1375,7 +1375,10 @@ char * sa2str(const struct sockaddr_storage *addr, int port, int map_ports)
 	default:
 		return NULL;
 	}
-	inet_ntop(addr->ss_family, ptr, buffer, sizeof(buffer));
+	if (inet_ntop(addr->ss_family, ptr, buffer, sizeof(buffer)) == NULL) {
+		BUG_ON(errno == ENOSPC);
+		return NULL;
+	}
 	if (map_ports)
 		return memprintf(&out, "%s:%+d", buffer, port);
 	else