diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 96f4a799..d2e2defd 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -239,6 +239,8 @@ getJasmineRequireObj().Spec = function() {
     this.queueRunner = attrs.queueRunner || function() {};
     this.catchingExceptions = attrs.catchingExceptions || function() { return true; };
 
+    this.timer = attrs.timer || {setTimeout: setTimeout, clearTimeout: clearTimeout};
+
     if (!this.fn) {
       this.pend();
     }
@@ -274,9 +276,26 @@ getJasmineRequireObj().Spec = function() {
       return;
     }
 
+    function timeoutable(fn) {
+      return function(done) {
+        var timeout = Function.prototype.apply.apply(self.timer.setTimeout, [window, [function() {
+          onException(new Error('timeout'));
+          done();
+        }, 10000]]);
+
+        var callDone = function() {
+          Function.prototype.apply.apply(self.timer.clearTimeout, [window, [timeout]]);
+          done();
+        };
+
+        fn(callDone); //TODO: do we care about more than 1 arg?
+      };
+    }
+
     var befores = this.beforeFns() || [],
-        afters = this.afterFns() || [];
-    var allFns = befores.concat(this.fn).concat(afters);
+        afters = this.afterFns() || [],
+        thisOne = (this.fn.length) ? timeoutable(this.fn) : this.fn;
+    var allFns = befores.concat(thisOne).concat(afters);
 
     this.queueRunner({
       fns: allFns,
@@ -360,6 +379,7 @@ getJasmineRequireObj().Env = function(j$) {
     var catchExceptions = true;
 
     var realSetTimeout = j$.getGlobal().setTimeout;
+    var realClearTimeout = j$.getGlobal().clearTimeout;
     this.clock = new j$.Clock(global, new j$.DelayedFunctionScheduler());
 
     var spies = [];
@@ -495,7 +515,8 @@ getJasmineRequireObj().Env = function(j$) {
         description: description,
         expectationResultFactory: expectationResultFactory,
         queueRunner: queueRunnerFactory,
-        fn: fn
+        fn: fn,
+        timer: {setTimeout: realSetTimeout, clearTimeout: realClearTimeout}
       });
 
       if (!self.specFilter(spec)) {
diff --git a/spec/core/EnvSpec.js b/spec/core/EnvSpec.js
index 9fb5b08e..09d32453 100644
--- a/spec/core/EnvSpec.js
+++ b/spec/core/EnvSpec.js
@@ -292,6 +292,55 @@ describe("Env integration", function() {
     env.execute();
   });
 
+  describe("with a mock clock", function() {
+      beforeEach(function() {
+          jasmine.getEnv().clock.install();
+      });
+
+      afterEach(function() {
+          jasmine.getEnv().clock.uninstall();
+      });
+
+      it("should not hang on async specs that forget to call done()", function(done) {
+          var env = new j$.Env(),
+          reporter = jasmine.createSpyObj('fakeReporter', [
+              "jasmineStarted",
+              "jasmineDone",
+              "suiteStarted",
+              "suiteDone",
+              "specStarted",
+              "specDone"
+              ]);
+
+          env.addReporter(reporter);
+
+          env.describe("tests", function() {
+              env.it("async spec that will hang", function(underTestCallback) {
+                  env.expect(true).toBeTruthy();
+              });
+
+              env.it("after async spec", function() {
+                  env.expect(true).toBeTruthy();
+              });
+          });
+
+          env.execute();
+
+          reporter.jasmineDone.and.callFake(function() {
+              expect(reporter.jasmineStarted).toHaveBeenCalledWith({
+                  totalSpecsDefined: 2
+              });
+
+              expect(reporter.specDone).toHaveBeenCalledWith(jasmine.objectContaining({status: 'passed'}));
+              expect(reporter.specDone).toHaveBeenCalledWith(jasmine.objectContaining({status: 'failed'}));
+
+              done();
+          });
+
+          jasmine.getEnv().clock.tick(60001);
+      });
+  });
+
   // TODO: something is wrong with this spec
   it("should report as expected", function(done) {
     var env = new j$.Env(),
diff --git a/src/core/Env.js b/src/core/Env.js
index 3294cbcd..20436edc 100644
--- a/src/core/Env.js
+++ b/src/core/Env.js
@@ -8,6 +8,7 @@ getJasmineRequireObj().Env = function(j$) {
     var catchExceptions = true;
 
     var realSetTimeout = j$.getGlobal().setTimeout;
+    var realClearTimeout = j$.getGlobal().clearTimeout;
     this.clock = new j$.Clock(global, new j$.DelayedFunctionScheduler());
 
     var spies = [];
@@ -143,7 +144,8 @@ getJasmineRequireObj().Env = function(j$) {
         description: description,
         expectationResultFactory: expectationResultFactory,
         queueRunner: queueRunnerFactory,
-        fn: fn
+        fn: fn,
+        timer: {setTimeout: realSetTimeout, clearTimeout: realClearTimeout}
       });
 
       if (!self.specFilter(spec)) {
diff --git a/src/core/Spec.js b/src/core/Spec.js
index d5c539de..27b11087 100644
--- a/src/core/Spec.js
+++ b/src/core/Spec.js
@@ -16,6 +16,8 @@ getJasmineRequireObj().Spec = function() {
     this.queueRunner = attrs.queueRunner || function() {};
     this.catchingExceptions = attrs.catchingExceptions || function() { return true; };
 
+    this.timer = attrs.timer || {setTimeout: setTimeout, clearTimeout: clearTimeout};
+
     if (!this.fn) {
       this.pend();
     }
@@ -51,9 +53,26 @@ getJasmineRequireObj().Spec = function() {
       return;
     }
 
+    function timeoutable(fn) {
+      return function(done) {
+        var timeout = Function.prototype.apply.apply(self.timer.setTimeout, [window, [function() {
+          onException(new Error('timeout'));
+          done();
+        }, 10000]]);
+
+        var callDone = function() {
+          Function.prototype.apply.apply(self.timer.clearTimeout, [window, [timeout]]);
+          done();
+        };
+
+        fn(callDone); //TODO: do we care about more than 1 arg?
+      };
+    }
+
     var befores = this.beforeFns() || [],
-        afters = this.afterFns() || [];
-    var allFns = befores.concat(this.fn).concat(afters);
+        afters = this.afterFns() || [],
+        thisOne = (this.fn.length) ? timeoutable(this.fn) : this.fn;
+    var allFns = befores.concat(thisOne).concat(afters);
 
     this.queueRunner({
       fns: allFns,