diff --git a/lib/reporters/base.js b/lib/reporters/base.js
index 172d489785..f3a4e67ca3 100644
--- a/lib/reporters/base.js
+++ b/lib/reporters/base.js
@@ -302,7 +302,7 @@ function Base (runner) {
     failures.push(test);
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     stats.end = new Date();
     stats.duration = stats.end - stats.start;
   });
diff --git a/lib/reporters/dot.js b/lib/reporters/dot.js
index 81e106edd0..3ccbce9ad3 100644
--- a/lib/reporters/dot.js
+++ b/lib/reporters/dot.js
@@ -56,7 +56,7 @@ function Dot (runner) {
     process.stdout.write(color('fail', Base.symbols.bang));
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     console.log();
     self.epilogue();
   });
diff --git a/lib/reporters/json-stream.js b/lib/reporters/json-stream.js
index c0d79cf970..af3e86d259 100644
--- a/lib/reporters/json-stream.js
+++ b/lib/reporters/json-stream.js
@@ -39,7 +39,7 @@ function List (runner) {
     console.log(JSON.stringify(['fail', test]));
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     process.stdout.write(JSON.stringify(['end', self.stats]));
   });
 }
diff --git a/lib/reporters/json.js b/lib/reporters/json.js
index 259a782121..97989ccbb3 100644
--- a/lib/reporters/json.js
+++ b/lib/reporters/json.js
@@ -43,7 +43,7 @@ function JSONReporter (runner) {
     pending.push(test);
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     var obj = {
       stats: self.stats,
       tests: tests.map(clean),
diff --git a/lib/reporters/landing.js b/lib/reporters/landing.js
index b8c7b5f20c..3cc036421d 100644
--- a/lib/reporters/landing.js
+++ b/lib/reporters/landing.js
@@ -81,7 +81,7 @@ function Landing (runner) {
     stream.write('\u001b[0m');
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     cursor.show();
     console.log();
     self.epilogue();
diff --git a/lib/reporters/list.js b/lib/reporters/list.js
index a562cdb94c..719ec0166c 100644
--- a/lib/reporters/list.js
+++ b/lib/reporters/list.js
@@ -54,7 +54,7 @@ function List (runner) {
     console.log(color('fail', '  %d) %s'), ++n, test.fullTitle());
   });
 
-  runner.on('end', self.epilogue.bind(self));
+  runner.once('end', self.epilogue.bind(self));
 }
 
 /**
diff --git a/lib/reporters/markdown.js b/lib/reporters/markdown.js
index 9c06616ea9..2c27e1dc25 100644
--- a/lib/reporters/markdown.js
+++ b/lib/reporters/markdown.js
@@ -91,7 +91,7 @@ function Markdown (runner) {
     buf += '```\n\n';
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     process.stdout.write('# TOC\n');
     process.stdout.write(generateTOC(runner.suite));
     process.stdout.write(buf);
diff --git a/lib/reporters/min.js b/lib/reporters/min.js
index 0d772f9601..2573a43450 100644
--- a/lib/reporters/min.js
+++ b/lib/reporters/min.js
@@ -29,7 +29,7 @@ function Min (runner) {
     process.stdout.write('\u001b[1;3H');
   });
 
-  runner.on('end', this.epilogue.bind(this));
+  runner.once('end', this.epilogue.bind(this));
 }
 
 /**
diff --git a/lib/reporters/nyan.js b/lib/reporters/nyan.js
index 1be49a97b9..77478ebd51 100644
--- a/lib/reporters/nyan.js
+++ b/lib/reporters/nyan.js
@@ -52,7 +52,7 @@ function NyanCat (runner) {
     self.draw();
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     Base.cursor.show();
     for (var i = 0; i < self.numberOfLines; i++) {
       write('\n');
diff --git a/lib/reporters/progress.js b/lib/reporters/progress.js
index 9d545534bc..27b79f99e3 100644
--- a/lib/reporters/progress.js
+++ b/lib/reporters/progress.js
@@ -80,7 +80,7 @@ function Progress (runner, options) {
 
   // tests are complete, output some stats
   // and the failures if any
-  runner.on('end', function () {
+  runner.once('end', function () {
     cursor.show();
     console.log();
     self.epilogue();
diff --git a/lib/reporters/spec.js b/lib/reporters/spec.js
index 993aff8dd3..d0543a5360 100644
--- a/lib/reporters/spec.js
+++ b/lib/reporters/spec.js
@@ -72,7 +72,7 @@ function Spec (runner) {
     console.log(indent() + color('fail', '  %d) %s'), ++n, test.title);
   });
 
-  runner.on('end', self.epilogue.bind(self));
+  runner.once('end', self.epilogue.bind(self));
 }
 
 /**
diff --git a/lib/reporters/tap.js b/lib/reporters/tap.js
index e37ac1b16f..4e99165f8f 100644
--- a/lib/reporters/tap.js
+++ b/lib/reporters/tap.js
@@ -51,7 +51,7 @@ function TAP (runner) {
     }
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     console.log('# tests ' + (passes + failures));
     console.log('# pass ' + passes);
     console.log('# fail ' + failures);
diff --git a/lib/reporters/xunit.js b/lib/reporters/xunit.js
index 7d98815ca2..faf96adac1 100644
--- a/lib/reporters/xunit.js
+++ b/lib/reporters/xunit.js
@@ -78,7 +78,7 @@ function XUnit (runner, options) {
     tests.push(test);
   });
 
-  runner.on('end', function () {
+  runner.once('end', function () {
     self.write(tag('testsuite', {
       name: suiteName,
       tests: stats.tests,
diff --git a/lib/runnable.js b/lib/runnable.js
index e8ca41800f..1045b0680b 100644
--- a/lib/runnable.js
+++ b/lib/runnable.js
@@ -142,6 +142,24 @@ Runnable.prototype.isPending = function () {
   return this.pending || (this.parent && this.parent.isPending());
 };
 
+/**
+ * Return `true` if this Runnable has failed.
+ * @return {boolean}
+ * @private
+ */
+Runnable.prototype.isFailed = function () {
+  return !this.isPending() && this.state === 'failed';
+};
+
+/**
+ * Return `true` if this Runnable has passed.
+ * @return {boolean}
+ * @private
+ */
+Runnable.prototype.isPassed = function () {
+  return !this.isPending() && this.state === 'passed';
+};
+
 /**
  * Set or get number of retries.
  *
diff --git a/lib/runner.js b/lib/runner.js
index 2e74c985fe..5a7e3e03e0 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -726,21 +726,25 @@ Runner.prototype.uncaught = function (err) {
 
   runnable.clearTimeout();
 
-  // Ignore errors if complete or pending
-  if (runnable.state || runnable.isPending()) {
+  // Ignore errors if already failed or pending
+  // See #3226
+  if (runnable.isFailed() || runnable.isPending()) {
     return;
   }
+  // we cannot recover gracefully if a Runnable has already passed
+  // then fails asynchronously
+  var alreadyPassed = runnable.isPassed();
+  // this will change the state to "failed" regardless of the current value
   this.fail(runnable, err);
+  if (!alreadyPassed) {
+    // recover from test
+    if (runnable.type === 'test') {
+      this.emit('test end', runnable);
+      this.hookUp('afterEach', this.next);
+      return;
+    }
 
-  // recover from test
-  if (runnable.type === 'test') {
-    this.emit('test end', runnable);
-    this.hookUp('afterEach', this.next);
-    return;
-  }
-
-  // recover from hooks
-  if (runnable.type === 'hook') {
+    // recover from hooks
     var errSuite = this.suite;
     // if hook failure is in afterEach block
     if (runnable.fullTitle().indexOf('after each') > -1) {
diff --git a/test/integration/fixtures/uncaught-fatal.fixture.js b/test/integration/fixtures/uncaught-fatal.fixture.js
new file mode 100644
index 0000000000..10be283816
--- /dev/null
+++ b/test/integration/fixtures/uncaught-fatal.fixture.js
@@ -0,0 +1,11 @@
+'use strict';
+
+it('should bail if a successful test asynchronously fails', function(done) {
+  done();
+  process.nextTick(function () {
+    throw new Error('global error');
+  });
+});
+
+it('should not actually get run', function () {
+});
diff --git a/test/integration/uncaught.spec.js b/test/integration/uncaught.spec.js
index 9a3dadbbbd..db495a923a 100644
--- a/test/integration/uncaught.spec.js
+++ b/test/integration/uncaught.spec.js
@@ -40,4 +40,24 @@ describe('uncaught exceptions', function () {
       done();
     });
   });
+
+  it('handles uncaught exceptions from which Mocha cannot recover', function (done) {
+    run('uncaught-fatal.fixture.js', args, function (err, res) {
+      if (err) {
+        done(err);
+        return;
+      }
+      assert.equal(res.stats.pending, 0);
+      assert.equal(res.stats.passes, 1);
+      assert.equal(res.stats.failures, 1);
+
+      assert.equal(res.failures[0].title,
+        'should bail if a successful test asynchronously fails');
+      assert.equal(res.passes[0].title,
+        'should bail if a successful test asynchronously fails');
+
+      assert.equal(res.code, 1);
+      done();
+    });
+  });
 });
diff --git a/test/reporters/doc.spec.js b/test/reporters/doc.spec.js
index aadd826c0e..484b26fca3 100644
--- a/test/reporters/doc.spec.js
+++ b/test/reporters/doc.spec.js
@@ -6,9 +6,10 @@ var Doc = reporters.Doc;
 describe('Doc reporter', function () {
   var stdout;
   var stdoutWrite;
-  var runner = {};
+  var runner;
   beforeEach(function () {
     stdout = [];
+    runner = {};
     stdoutWrite = process.stdout.write;
     process.stdout.write = function (string) {
       stdout.push(string);
@@ -24,7 +25,7 @@ describe('Doc reporter', function () {
         title: expectedTitle
       };
       it('should log html with indents and expected title', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'suite') {
             callback(suite);
           }
@@ -44,7 +45,7 @@ describe('Doc reporter', function () {
           title: unescapedTitle
         };
         expectedTitle = '&#x3C;div&#x3E;' + expectedTitle + '&#x3C;/div&#x3E;';
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'suite') {
             callback(suite);
           }
@@ -64,7 +65,7 @@ describe('Doc reporter', function () {
         root: true
       };
       it('should not log any html', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'suite') {
             callback(suite);
           }
@@ -82,7 +83,7 @@ describe('Doc reporter', function () {
         root: false
       };
       it('should log expected html with indents', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'suite end') {
             callback(suite);
           }
@@ -100,7 +101,7 @@ describe('Doc reporter', function () {
         root: true
       };
       it('should not log any html', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'suite end') {
             callback(suite);
           }
@@ -123,7 +124,7 @@ describe('Doc reporter', function () {
       }
     };
     it('should log html with indents and expected title and body', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(test);
         }
@@ -144,7 +145,7 @@ describe('Doc reporter', function () {
 
       var expectedEscapedTitle = '&#x3C;div&#x3E;' + expectedTitle + '&#x3C;/div&#x3E;';
       var expectedEscapedBody = '&#x3C;div&#x3E;' + expectedBody + '&#x3C;/div&#x3E;';
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(test);
         }
@@ -171,7 +172,7 @@ describe('Doc reporter', function () {
       }
     };
     it('should log html with indents and expected title, body and error', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test, expectedError);
         }
@@ -195,7 +196,7 @@ describe('Doc reporter', function () {
       var expectedEscapedTitle = '&#x3C;div&#x3E;' + expectedTitle + '&#x3C;/div&#x3E;';
       var expectedEscapedBody = '&#x3C;div&#x3E;' + expectedBody + '&#x3C;/div&#x3E;';
       var expectedEscapedError = '&#x3C;div&#x3E;' + expectedError + '&#x3C;/div&#x3E;';
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test, unescapedError);
         }
diff --git a/test/reporters/dot.spec.js b/test/reporters/dot.spec.js
index 8baccac453..47d3581723 100644
--- a/test/reporters/dot.spec.js
+++ b/test/reporters/dot.spec.js
@@ -31,7 +31,7 @@ describe('Dot reporter', function () {
 
   describe('on start', function () {
     it('should return a new line', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -50,7 +50,7 @@ describe('Dot reporter', function () {
         Base.window.width = 2;
       });
       it('should return a new line and then a coma', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pending') {
             callback();
           }
@@ -66,7 +66,7 @@ describe('Dot reporter', function () {
     });
     describe('if window width is equal to or less than 1', function () {
       it('should return a coma', function () {
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pending') {
             callback();
           }
@@ -91,7 +91,7 @@ describe('Dot reporter', function () {
             duration: 1,
             slow: function () { return 2; }
           };
-          runner.on = function (event, callback) {
+          runner.on = runner.once = function (event, callback) {
             if (event === 'pass') {
               callback(test);
             }
@@ -113,7 +113,7 @@ describe('Dot reporter', function () {
             duration: 1,
             slow: function () { return 2; }
           };
-          runner.on = function (event, callback) {
+          runner.on = runner.once = function (event, callback) {
             if (event === 'pass') {
               callback(test);
             }
@@ -132,7 +132,7 @@ describe('Dot reporter', function () {
             duration: 2,
             slow: function () { return 1; }
           };
-          runner.on = function (event, callback) {
+          runner.on = runner.once = function (event, callback) {
             if (event === 'pass') {
               callback(test);
             }
@@ -158,7 +158,7 @@ describe('Dot reporter', function () {
             err: 'some error'
           }
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'fail') {
             callback(test);
           }
@@ -179,7 +179,7 @@ describe('Dot reporter', function () {
             err: 'some error'
           }
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'fail') {
             callback(test);
           }
@@ -195,7 +195,7 @@ describe('Dot reporter', function () {
   });
   describe('on end', function () {
     it('should call the epilogue', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/json-stream.spec.js b/test/reporters/json-stream.spec.js
index 049b3f6381..4ad6f65efb 100644
--- a/test/reporters/json-stream.spec.js
+++ b/test/reporters/json-stream.spec.js
@@ -19,7 +19,7 @@ describe('Json Stream reporter', function () {
 
   describe('on start', function () {
     it('should write stringified start with expected total', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -47,7 +47,7 @@ describe('Json Stream reporter', function () {
         currentRetry: function () { return currentRetry; },
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(expectedTest);
         }
@@ -80,7 +80,7 @@ describe('Json Stream reporter', function () {
           message: expectedErrorMessage,
           stack: expectedErrorStack
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'fail') {
             callback(expectedTest, expectedError);
           }
@@ -109,7 +109,7 @@ describe('Json Stream reporter', function () {
         var expectedError = {
           message: expectedErrorMessage
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'fail') {
             callback(expectedTest, expectedError);
           }
@@ -125,7 +125,7 @@ describe('Json Stream reporter', function () {
 
   describe('on end', function () {
     it('should write end details', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/landing.spec.js b/test/reporters/landing.spec.js
index 9a171e34e3..f055d15d6c 100644
--- a/test/reporters/landing.spec.js
+++ b/test/reporters/landing.spec.js
@@ -34,7 +34,7 @@ describe('Landing reporter', function () {
     it('should write new lines', function () {
       var cachedCursor = Base.cursor;
       Base.cursor.hide = function () {};
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -53,7 +53,7 @@ describe('Landing reporter', function () {
       Base.cursor.hide = function () {
         calledCursorHide = true;
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -73,7 +73,7 @@ describe('Landing reporter', function () {
         var test = {
           state: 'failed'
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback(test);
           }
@@ -101,7 +101,7 @@ describe('Landing reporter', function () {
         var test = {
           state: 'success'
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback(test);
           }
@@ -132,7 +132,7 @@ describe('Landing reporter', function () {
       Base.cursor.show = function () {
         calledCursorShow = true;
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/list.spec.js b/test/reporters/list.spec.js
index 87978de011..ce862f5f2b 100644
--- a/test/reporters/list.spec.js
+++ b/test/reporters/list.spec.js
@@ -33,7 +33,7 @@ describe('List reporter', function () {
           return expectedTitle;
         }
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -61,7 +61,7 @@ describe('List reporter', function () {
           return expectedTitle;
         }
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pending') {
           callback(test);
         }
@@ -89,7 +89,7 @@ describe('List reporter', function () {
         duration: expectedDuration,
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(test);
         }
@@ -117,7 +117,7 @@ describe('List reporter', function () {
         duration: expectedDuration,
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(test);
         }
@@ -148,7 +148,7 @@ describe('List reporter', function () {
         duration: expectedDuration,
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test);
         }
@@ -174,12 +174,12 @@ describe('List reporter', function () {
         duration: expectedDuration,
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test);
         }
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test);
         }
@@ -198,7 +198,7 @@ describe('List reporter', function () {
       var test = {};
       var checked = false;
       var err;
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (!checked && event === 'fail') {
           err = new Error('fake failure object with actual/expected');
           err.actual = actual;
@@ -219,7 +219,7 @@ describe('List reporter', function () {
   describe('on end', function () {
     it('should call epilogue', function () {
       var calledEpilogue = false;
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/markdown.spec.js b/test/reporters/markdown.spec.js
index 4971122ce3..51958e75f9 100644
--- a/test/reporters/markdown.spec.js
+++ b/test/reporters/markdown.spec.js
@@ -31,7 +31,7 @@ describe('Markdown reporter', function () {
           suites: []
         }]
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'suite') {
           callback(expectedSuite);
         }
@@ -76,7 +76,7 @@ describe('Markdown reporter', function () {
         slow: function () {},
         body: expectedBody
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pass') {
           callback(expectedTest);
         }
diff --git a/test/reporters/min.spec.js b/test/reporters/min.spec.js
index e19ca0bec1..47e3211080 100644
--- a/test/reporters/min.spec.js
+++ b/test/reporters/min.spec.js
@@ -19,7 +19,7 @@ describe('Min reporter', function () {
 
   describe('on start', function () {
     it('should clear screen then set cursor position', function () {
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -38,7 +38,7 @@ describe('Min reporter', function () {
   describe('on end', function () {
     it('should call epilogue', function () {
       var calledEpilogue = false;
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/nyan.spec.js b/test/reporters/nyan.spec.js
index b90c3e3af4..9192f0ec14 100644
--- a/test/reporters/nyan.spec.js
+++ b/test/reporters/nyan.spec.js
@@ -22,7 +22,7 @@ describe('Nyan reporter', function () {
     describe('on start', function () {
       it('should call draw', function () {
         var calledDraw = false;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'start') {
             callback();
           }
@@ -41,7 +41,7 @@ describe('Nyan reporter', function () {
     describe('on pending', function () {
       it('should call draw', function () {
         var calledDraw = false;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pending') {
             callback();
           }
@@ -60,7 +60,7 @@ describe('Nyan reporter', function () {
     describe('on pass', function () {
       it('should call draw', function () {
         var calledDraw = false;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pass') {
             var test = {
               duration: '',
@@ -83,7 +83,7 @@ describe('Nyan reporter', function () {
     describe('on fail', function () {
       it('should call draw', function () {
         var calledDraw = false;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'fail') {
             var test = {
               err: ''
@@ -105,7 +105,7 @@ describe('Nyan reporter', function () {
     describe('on end', function () {
       it('should call epilogue', function () {
         var calledEpilogue = false;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'end') {
             callback();
           }
@@ -123,7 +123,7 @@ describe('Nyan reporter', function () {
       });
       it('should write numberOfLines amount of new lines', function () {
         var expectedNumberOfLines = 4;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'end') {
             callback();
           }
@@ -145,7 +145,7 @@ describe('Nyan reporter', function () {
         Base.cursor.show = function () {
           showCalled = true;
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'end') {
             callback();
           }
@@ -177,7 +177,7 @@ describe('Nyan reporter', function () {
 
     describe('if tick is false', function () {
       it('should draw face with expected spaces, _ and ^', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         nyanCat.stats = { passes: 2, pending: 1, failures: 0 };
 
         nyanCat.draw.call({
@@ -213,7 +213,7 @@ describe('Nyan reporter', function () {
     });
     describe('if tick is true', function () {
       it('should draw face with expected spaces, _ and ~', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         nyanCat.stats = { passes: 2, pending: 1, failures: 0 };
 
         nyanCat.draw.call({
@@ -262,7 +262,7 @@ describe('Nyan reporter', function () {
     });
 
     it('should write cursor down interaction with expected number', function () {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       var expectedNumber = 25;
 
       nyanCat.cursorDown(expectedNumber);
@@ -287,7 +287,7 @@ describe('Nyan reporter', function () {
     });
 
     it('should write cursor up interaction with expected number', function () {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       var expectedNumber = 25;
 
       nyanCat.cursorUp(expectedNumber);
@@ -313,7 +313,7 @@ describe('Nyan reporter', function () {
       });
 
       it('should return argument string', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         var expectedString = 'hello';
         var outputString = nyanCat.rainbowify(expectedString);
 
@@ -334,7 +334,7 @@ describe('Nyan reporter', function () {
       it('should return rainbowified string from the given string and predefined codes', function () {
         var startCode = '\u001b[38;5;';
         var endCode = '\u001b[0m';
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         var expectedString = 'hello';
         var colorCode = 'somecode';
         var expectedRainbowifyString = startCode + colorCode + 'm' + expectedString + endCode;
@@ -353,7 +353,7 @@ describe('Nyan reporter', function () {
   describe('appendRainbow', function () {
     describe('if tick is true', function () {
       it('should set an _ segment', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         var expectedSegment;
         var inputArray = [];
         var trajectories = [inputArray, inputArray, inputArray, inputArray];
@@ -370,7 +370,7 @@ describe('Nyan reporter', function () {
         expect(expectedSegment).to.equal('_');
       });
       it('should shift each trajectory item, if its length is greater of equal to its max width', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
 
         var rainbowifyResult = 'rainbowify';
         var inputArray = ['itemToShify'];
@@ -390,7 +390,7 @@ describe('Nyan reporter', function () {
     });
     describe('if tick is false', function () {
       it('should set an - segment', function () {
-        var nyanCat = new NyanCat({on: function () {}});
+        var nyanCat = new NyanCat({on: function () {}, once: function () {}});
         var expectedSegment;
         var inputArray = [];
         var trajectories = [inputArray, inputArray, inputArray, inputArray];
@@ -424,7 +424,7 @@ describe('Nyan reporter', function () {
       var passes = 2;
       var pending = 1;
       var failures = 1;
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.drawScoreboard.call({
         cursorUp: function () {},
         stats: { passes: passes, pending: pending, failures: failures },
@@ -455,7 +455,7 @@ describe('Nyan reporter', function () {
       var expectedCursorArgument = null;
       var expectedNumberOfLines = 1000;
 
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.drawScoreboard.call({
         cursorUp: function (lines) {
           expectedCursorArgument = lines;
@@ -481,7 +481,7 @@ describe('Nyan reporter', function () {
       var expectedContents = 'input';
       var inputArray = [expectedContents];
       var trajectories = [inputArray];
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.drawRainbow.call({
         cursorUp: function () {},
         trajectories: trajectories,
@@ -507,7 +507,7 @@ describe('Nyan reporter', function () {
       var expectedCursorArgument = null;
       var expectedNumberOfLines = 1000;
 
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.drawRainbow.call({
         cursorUp: function (lines) {
           expectedCursorArgument = lines;
@@ -523,25 +523,25 @@ describe('Nyan reporter', function () {
   });
   describe('face', function () {
     it('expected face:(x .x) when "failures" at least one', function () {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.stats = { passes: 2, pending: 1, failures: 1 };
       expect(nyanCat.face()).to.equal('( x .x)');
     });
 
     it('expected face:(x .x) when "pending" at least one and no failing', function () {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.stats = { passes: 2, pending: 1, failures: 0 };
       expect(nyanCat.face()).to.equal('( o .o)');
     });
 
     it('expected face:(^ .^) when "passing" only', function () {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.stats = { passes: 1, pending: 0, failures: 0 };
       expect(nyanCat.face()).to.equal('( ^ .^)');
     });
 
     it('expected face:(- .-) when otherwise', function (done) {
-      var nyanCat = new NyanCat({on: function () {}});
+      var nyanCat = new NyanCat({on: function () {}, once: function () {}});
       nyanCat.stats = { passes: 0, pending: 0, failures: 0 };
       expect(nyanCat.face()).to.equal('( - .-)');
       done();
diff --git a/test/reporters/progress.spec.js b/test/reporters/progress.spec.js
index 45ab2f42b8..02c4b723dd 100644
--- a/test/reporters/progress.spec.js
+++ b/test/reporters/progress.spec.js
@@ -25,7 +25,7 @@ describe('Progress reporter', function () {
       Base.cursor.hide = function () {
         calledCursorHide = true;
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -52,7 +52,7 @@ describe('Progress reporter', function () {
         var expectedTotal = 1;
         var expectedOptions = {};
         runner.total = expectedTotal;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback();
           }
@@ -94,7 +94,7 @@ describe('Progress reporter', function () {
           reporterOptions: expectedOptions
         };
         runner.total = expectedTotal;
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback();
           }
@@ -126,7 +126,7 @@ describe('Progress reporter', function () {
       Base.cursor.show = function () {
         calledCursorShow = true;
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'end') {
           callback();
         }
diff --git a/test/reporters/spec.spec.js b/test/reporters/spec.spec.js
index 70a68169ad..f3cfd6c220 100644
--- a/test/reporters/spec.spec.js
+++ b/test/reporters/spec.spec.js
@@ -31,7 +31,7 @@ describe('Spec reporter', function () {
       var suite = {
         title: expectedTitle
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'suite') {
           callback(suite);
         }
@@ -50,7 +50,7 @@ describe('Spec reporter', function () {
       var suite = {
         title: expectedTitle
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pending') {
           callback(suite);
         }
@@ -73,7 +73,7 @@ describe('Spec reporter', function () {
           duration: expectedDuration,
           slow: function () { return 1; }
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pass') {
             callback(test);
           }
@@ -93,7 +93,7 @@ describe('Spec reporter', function () {
           duration: expectedDuration,
           slow: function () { return 2; }
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'pass') {
             callback(test);
           }
@@ -112,7 +112,7 @@ describe('Spec reporter', function () {
       var test = {
         title: expectedTitle
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test);
         }
diff --git a/test/reporters/tap.spec.js b/test/reporters/tap.spec.js
index 13ddc8e521..84a4875f46 100644
--- a/test/reporters/tap.spec.js
+++ b/test/reporters/tap.spec.js
@@ -22,7 +22,7 @@ describe('TAP reporter', function () {
       var expectedSuite = 'some suite';
       var expectedTotal = 10;
       var expectedString;
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'start') {
           callback();
         }
@@ -53,7 +53,7 @@ describe('TAP reporter', function () {
           return expectedTitle;
         }
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'test end') {
           callback();
         }
@@ -82,7 +82,7 @@ describe('TAP reporter', function () {
         },
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'test end') {
           callback();
         }
@@ -116,7 +116,7 @@ describe('TAP reporter', function () {
         var error = {
           stack: expectedStack
         };
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback();
           }
@@ -148,7 +148,7 @@ describe('TAP reporter', function () {
           slow: function () {}
         };
         var error = {};
-        runner.on = function (event, callback) {
+        runner.on = runner.once = function (event, callback) {
           if (event === 'test end') {
             callback();
           }
@@ -181,7 +181,7 @@ describe('TAP reporter', function () {
         },
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'fail') {
           callback(test, {});
         }
diff --git a/test/reporters/xunit.spec.js b/test/reporters/xunit.spec.js
index 12021a11c8..916f3e650b 100644
--- a/test/reporters/xunit.spec.js
+++ b/test/reporters/xunit.spec.js
@@ -15,7 +15,8 @@ describe('XUnit reporter', function () {
   beforeEach(function () {
     stdout = [];
     runner = {
-      on: function () {}
+      on: function () {},
+      once: function () {}
     };
   });
 
@@ -75,7 +76,7 @@ describe('XUnit reporter', function () {
         name: 'pass',
         slow: function () {}
       };
-      runner.on = function (event, callback) {
+      runner.on = runner.once = function (event, callback) {
         if (event === 'pending') {
           callback(pendingTest);
         }
@@ -110,7 +111,7 @@ describe('XUnit reporter', function () {
   describe('done', function () {
     describe('if fileStream is truthly', function () {
       it('should run callback with failure inside streams end', function () {
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
         var callbackArgument = null;
         var callback = function (failures) {
           callbackArgument = failures;
@@ -135,7 +136,7 @@ describe('XUnit reporter', function () {
     });
     describe('if fileStream is falsy', function () {
       it('should run callback with failure', function () {
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
         var callbackArgument = null;
         var callback = function (failures) {
           callbackArgument = failures;
@@ -156,7 +157,7 @@ describe('XUnit reporter', function () {
     describe('if fileStream is truthly', function () {
       it('should call fileStream write with line and new line', function () {
         var expectedWrite = null;
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
         var fileStream = {
           write: function (write) {
             expectedWrite = write;
@@ -178,7 +179,7 @@ describe('XUnit reporter', function () {
           stdout.push(string);
         };
 
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
         var expectedLine = 'some-line';
         xunit.write.call(
           { fileStream: false },
@@ -199,7 +200,7 @@ describe('XUnit reporter', function () {
           stdout.push(string);
         };
 
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
         var expectedLine = 'some-line';
         xunit.write.call(
           { fileStream: false },
@@ -216,7 +217,7 @@ describe('XUnit reporter', function () {
   describe('test', function () {
     describe('on test failure', function () {
       it('should write expected tag with error details', function () {
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
 
         var expectedWrite = null;
         var expectedClassName = 'fullTitle';
@@ -253,7 +254,7 @@ describe('XUnit reporter', function () {
     });
     describe('on test pending', function () {
       it('should write expected tag', function () {
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
 
         var expectedClassName = 'fullTitle';
         var expectedTitle = 'some title';
@@ -284,7 +285,7 @@ describe('XUnit reporter', function () {
     });
     describe('on test in any other state', function () {
       it('should write expected tag', function () {
-        var xunit = new XUnit({on: function () {}});
+        var xunit = new XUnit({on: function () {}, once: function () {}});
 
         var expectedClassName = 'fullTitle';
         var expectedTitle = 'some title';
@@ -337,6 +338,7 @@ describe('XUnit reporter', function () {
           events[eventName] = eventHandler;
         }
       };
+      runner.once = runner.on;
 
       lines = [];
       fileStream = {
diff --git a/test/unit/runnable.spec.js b/test/unit/runnable.spec.js
index b7f2cecb7a..06545e10a2 100644
--- a/test/unit/runnable.spec.js
+++ b/test/unit/runnable.spec.js
@@ -490,4 +490,37 @@ describe('Runnable(title, fn)', function () {
       });
     });
   });
+
+  describe('#isFailed()', function () {
+    it('should return `true` if test has not failed', function () {
+      var test = new Runnable('foo', function () {
+      });
+      // runner sets the state
+      test.run(function () {
+        expect(test.isFailed()).not.to.be.ok();
+      });
+    });
+
+    it('should return `true` if test has failed', function () {
+      var test = new Runnable('foo', function () {
+      });
+      // runner sets the state
+      test.state = 'failed';
+      test.run(function () {
+        expect(test.isFailed()).to.be.ok();
+      });
+    });
+
+    it('should return `false` if test is pending', function () {
+      var test = new Runnable('foo', function () {
+      });
+      // runner sets the state
+      test.isPending = function () {
+        return true;
+      };
+      test.run(function () {
+        expect(test.isFailed()).not.to.be.ok();
+      });
+    });
+  });
 });