diff --git a/content/base/test/test_websocket_basic.html b/content/base/test/test_websocket_basic.html
index 5dbd8ed0190..38c13c554d0 100644
--- a/content/base/test/test_websocket_basic.html
+++ b/content/base/test/test_websocket_basic.html
@@ -18,25 +18,24 @@ const kUrl = "ws://mochi.test:8888/tests/content/base/test/file_websocket_basic"
 
 var ws;
 
-var results = ["test", "/tests/content/base/test/file_websocket_basic", "http://mochi.test:8888", "end"];
-
 function forcegc() {
   SpecialPowers.forceGC();
   SpecialPowers.gc();
 }
 
-function finishWSTest() {
-  SimpleTest.finish();
-}
-
 function testWebSocket() {
-  testWebSocket1();
+  SimpleTest.executeSoon(testWebSocket1);
 }
 
 /**
  * Sends message keywords, then receives their values.
  */
 function testWebSocket1() {
+  var results = ["test",
+                 "/tests/content/base/test/file_websocket_basic",
+                 "http://mochi.test:8888",
+                 "end"];
+
   ws = new WebSocket(kUrl, "test");
   is(ws.url, kUrl, "[1] WebSocket.url");
   ws.onopen = function(e) {
@@ -51,11 +50,11 @@ function testWebSocket1() {
     is(results.length, 0, "[1] Number of unreceived messages");
     ok(e.wasClean, "[1] Connection closed cleanly");
 
-    testWebSocket2();
+    SimpleTest.executeSoon(testWebSocket2);
   };
   ws.onerror = function(e) {
     ok(false, "[1] onerror() should not have been called!");
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
   ws.onmessage = function(e) {
     document.getElementById('log').textContent += "\n" + e.data;
@@ -65,13 +64,13 @@ function testWebSocket1() {
 }
 
 /**
- * Sends 1000(+1) test messages, then receives them.
+ * Sends 1000+1 test messages, then receives them.
  */
 function testWebSocket2() {
   const testCount = 1000;
+  const testMessage = "test message 2.";
 
   var messageCount = 0;
-  var testMessage = "test message";
 
   ws = new WebSocket(kUrl, "test");
   ws.onopen = function(e) {
@@ -81,33 +80,33 @@ function testWebSocket2() {
     ws.send("end");
   };
   ws.onclose = function(e) {
-    is(messageCount, testCount, "[2] Number of received messages");
+    is(messageCount, testCount + 1, "[2] Number of received messages");
     ok(e.wasClean, "[2] Connection closed cleanly");
 
-    testWebSocket3();
+    SimpleTest.executeSoon(testWebSocket3);
   };
   ws.onerror = function(e) {
     ok(false, "[2] onerror() should not have been called!");
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
   ws.onmessage = function(e) {
     ++messageCount;
-    is(e.data, testMessage + messageCount, "[2] Received message");
+    if (messageCount > testCount)
+      is(e.data, "end", "[2] Received message");
+    else
+      is(e.data, testMessage + messageCount, "[2] Received message");
     document.getElementById('log').textContent = messageCount;
-    if (messageCount == testCount) {
-      this.onmessage = null;
-    }
   };
 }
 
 /**
- * Sends 100(+1) test messages, then receives them, calling forcegc() at each step.
+ * Sends 100+1 test messages, then receives them, calling forcegc() at each step.
  */
 function testWebSocket3() {
   const testCount = 100;
+  const testMessage = "test message 3.";
 
   var messageCount = 0;
-  var testMessage = "test message";
 
   ws = new WebSocket(kUrl, "test");
   ws.onopen = function(e) {
@@ -115,26 +114,27 @@ function testWebSocket3() {
       forcegc();
       ws.send(testMessage + i);
     }
+    forcegc();
     ws.send("end");
   };
   ws.onclose = function(e) {
-    is(messageCount, testCount, "[3] Number of received messages");
+    is(messageCount, testCount + 1, "[3] Number of received messages");
     ok(e.wasClean, "[3] Connection closed cleanly");
 
-    testWebSocket4();
+    SimpleTest.executeSoon(testWebSocket4);
   };
   ws.onerror = function(e) {
     ok(false, "[3] onerror() should not have been called!");
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
   ws.onmessage = function(e) {
     forcegc();
     ++messageCount;
-    is(e.data, testMessage + messageCount, "[3] Received message");
+    if (messageCount > testCount)
+      is(e.data, "end", "[3] Received message");
+    else
+      is(e.data, testMessage + messageCount, "[3] Received message");
     document.getElementById('log').textContent = messageCount;
-    if (messageCount == testCount) {
-      this.onmessage = null;
-    }
   };
 }
 
@@ -142,9 +142,10 @@ function testWebSocket3() {
  * Sends a huge test message, then receives it, then closes the WebSocket from client-side.
  */
 function testWebSocket4() {
+  // String length = 13 + ((10,000 - 1) * 26) + 11 = 259,998 = almost 254 KiB.
+  const longString = "messageStart " + new Array(10000).join(" -huge WebSocket message- ") + " messageEnd";
+
   ws = new WebSocket(kUrl, "test");
-  // String length = (10,000 - 1) * 23 = 229,977 = almost 225 KiB.
-  var longString = new Array(10000).join("-huge websocket message");
   ws.onopen = function(e) {
     is(this, ws, "[4, onopen()] 'this' should point to the WebSocket.");
     ws.send(longString);
@@ -153,12 +154,12 @@ function testWebSocket4() {
     is(this, ws, "[4, onclose()] 'this' should point to the WebSocket.");
     ok(e.wasClean, "[4] Connection closed cleanly");
 
-    testWebSocket5();
+    SimpleTest.executeSoon(testWebSocket5);
   };
   ws.onerror = function(e) {
     is(this, ws, "[4, onerror()] 'this' should point to the WebSocket.");
     ok(false, "[4, onerror()] should not have been called!");
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
   ws.onmessage = function(e) {
     is(this, ws, "[4, onmessage()] 'this' should point to the WebSocket.");
@@ -187,11 +188,11 @@ function testWebSocket5() {
     this.send(msg);
     is(this.bufferedAmount, msg.length, "[5] Length of buffered message sent after closing");
 
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
   ws.onerror = function(e) {
     ok(false, "[5] onerror() should not have been called!");
-    finishWSTest();
+    SimpleTest.executeSoon(SimpleTest.finish);
   };
 }