diff --git a/tools/tests/releases.js b/tools/tests/releases.js
index 20a9c5a9eb..fdd1f03567 100644
--- a/tools/tests/releases.js
+++ b/tools/tests/releases.js
@@ -194,7 +194,7 @@ selftest.define("checkout", ['checkout'], async function () {
   await s.cd('myapp', async function () {
     s.write(".meteor/release", "something");
     run = s.run("list");
-    run.readErr("=> Running Meteor from a checkout");
+    await run.readErr("=> Running Meteor from a checkout");
     await run.matchErr("project version");
     await run.matchErr("(Meteor something)\n");
     run.waitSecs(10);
diff --git a/tools/tool-testing/matcher.js b/tools/tool-testing/matcher.js
index 6523269cd0..4b0e4ef662 100644
--- a/tools/tool-testing/matcher.js
+++ b/tools/tool-testing/matcher.js
@@ -70,26 +70,13 @@ export default class Matcher {
     matchFullBuffer = false,
   }) {
     if (this.matchPromise) {
-      // wait a bit to let the matcher catch up
-      // [FIBERS]
-      // TODO: check this later
-      const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));
-      await sleep(100);
-
-      this._tryMatch(); // could clear this.matchPromise
-
-      // If we still have a matchPromise, then we have a problem.
-      // you should check who is calling.
-      if (this.matchPromise) {
-        return Promise.reject(new Error("already have a match pending?"))
-      }
+      return Promise.reject(new Error("already have a match pending?"));
     }
     this.matchPattern = pattern;
     this.matchStrict = strict;
     this.matchFullBuffer = matchFullBuffer;
-    this.matchPromise = makeFulfillablePromise();
-    const mp = this.matchPromise;
-    this._tryMatch(); // could clear this.matchPromise
+    const mp = this.matchPromise = makeFulfillablePromise();
+    await this._tryMatch(); // could clear this.matchPromise
 
     let timer = null;
     if (timeout) {