diff --git a/src/spawn.ts b/src/spawn.ts
index a50a39b..fe9b985 100644
--- a/src/spawn.ts
+++ b/src/spawn.ts
@@ -256,7 +256,10 @@ export function startCollator(
 		p[wsPort].stdout.pipe(log);
 		p[wsPort].stderr.on("data", function (chunk) {
 			let message = chunk.toString();
-			if (message.includes("Listening for new connections")) {
+			let ready =
+				message.includes("Running JSON-RPC WS server:") ||
+				message.includes("Listening for new connections");
+			if (ready) {
 				resolve();
 			}
 			log.write(message);
@@ -291,7 +294,10 @@ export function startSimpleCollator(
 		p[port].stdout.pipe(log);
 		p[port].stderr.on("data", function (chunk) {
 			let message = chunk.toString();
-			if (message.includes("Listening for new connections")) {
+			let ready =
+				message.includes("Running JSON-RPC WS server:") ||
+				message.includes("Listening for new connections");
+			if (ready) {
 				resolve();
 			}
 			log.write(message);