diff --git a/test/simple/test-debug-signal-cluster.js b/test/simple/test-debug-signal-cluster.js
index 27d53910b7..9e6edb803f 100644
--- a/test/simple/test-debug-signal-cluster.js
+++ b/test/simple/test-debug-signal-cluster.js
@@ -35,32 +35,32 @@ var pids = null;
 
 child.stderr.on('data', function(data) {
   var lines = data.toString().replace(/\r/g, '').trim().split('\n');
-  var line = lines[0];
 
-  lines.forEach(function(ln) { console.log('> ' + ln) } );
+  lines.forEach(function(line) {
+    console.log('> ' + line);
 
-  if (outputTimerId !== undefined)
-    clearTimeout(outputTimerId);
+    if (line === 'all workers are running') {
+      child.on('message', function(msg) {
+        if (msg.type !== 'pids')
+          return;
 
-  if (waitingForDebuggers) {
-    outputLines = outputLines.concat(lines);
-    outputTimerId = setTimeout(onNoMoreLines, 800);
-  } else if (line === 'all workers are running') {
-    child.on('message', function(msg) {
-      if (msg.type !== 'pids')
-        return;
+        pids = msg.pids;
+        console.error('got pids %j', pids);
 
-      pids = msg.pids;
-      console.error('got pids %j', pids);
+        waitingForDebuggers = true;
+        process._debugProcess(child.pid);
+      });
 
-      waitingForDebuggers = true;
-      process._debugProcess(child.pid);
-    });
+      child.send({
+        type: 'getpids'
+      });
+    } else if (waitingForDebuggers) {
+      outputLines.push(line);
+    }
 
-    child.send({
-      type: 'getpids'
-    });
-  }
+  });
+  if (outputLines.length >= expectedLines.length)
+    onNoMoreLines();
 });
 
 function onNoMoreLines() {
@@ -70,7 +70,7 @@ function onNoMoreLines() {
 
 setTimeout(function testTimedOut() {
   assert(false, 'test timed out.');
-}, 6000);
+}, 6000).unref();
 
 process.on('exit', function onExit() {
   pids.forEach(function(pid) {
@@ -78,16 +78,16 @@ process.on('exit', function onExit() {
   });
 });
 
-function assertOutputLines() {
-  var expectedLines = [
-    'Starting debugger agent.',
-    'Debugger listening on port ' + 5858,
-    'Starting debugger agent.',
-    'Debugger listening on port ' + 5859,
-    'Starting debugger agent.',
-    'Debugger listening on port ' + 5860,
-  ];
+var expectedLines = [
+  'Starting debugger agent.',
+  'Debugger listening on port ' + 5858,
+  'Starting debugger agent.',
+  'Debugger listening on port ' + 5859,
+  'Starting debugger agent.',
+  'Debugger listening on port ' + 5860,
+];
 
+function assertOutputLines() {
   // Do not assume any particular order of output messages,
   // since workers can take different amout of time to
   // start up