diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index f980d6c4..3eb4f61b 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -6471,13 +6471,25 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
         throw new Error('spyOnAllFunctions could not find an object to spy upon');
       }
 
-      for (var prop in obj) {
-        if (Object.prototype.hasOwnProperty.call(obj, prop) && obj[prop] instanceof Function) {
-          var descriptor = Object.getOwnPropertyDescriptor(obj, prop);
-          if ((descriptor.writable || descriptor.set) && descriptor.configurable) {
-            this.spyOn(obj, prop);
+      var pointer = obj,
+          props = [],
+          prop,
+          descriptor;
+
+      while (pointer) {
+        for (prop in pointer) {
+          if (Object.prototype.hasOwnProperty.call(pointer, prop) && pointer[prop] instanceof Function) {
+            descriptor = Object.getOwnPropertyDescriptor(pointer, prop);
+            if ((descriptor.writable || descriptor.set) && descriptor.configurable) {
+              props.push(prop);
+            }
           }
         }
+        pointer = Object.getPrototypeOf(pointer);
+      }
+
+      for (var i = 0; i < props.length; i++) {
+        this.spyOn(obj, props[i]);
       }
 
       return obj;
diff --git a/spec/core/SpyRegistrySpec.js b/spec/core/SpyRegistrySpec.js
index 920502d1..c7f53fe1 100644
--- a/spec/core/SpyRegistrySpec.js
+++ b/spec/core/SpyRegistrySpec.js
@@ -222,7 +222,7 @@ describe("SpyRegistry", function() {
       }).toThrowError(/spyOnAllFunctions could not find an object to spy upon/);
     });
 
-    it("overrides all writable and configurable functions of the object", function() {
+    it("overrides all writable and configurable functions of the object and its parents", function() {
       var spyRegistry = new jasmineUnderTest.SpyRegistry({createSpy: function() {
         return 'I am a spy';
       }});
@@ -234,7 +234,7 @@ describe("SpyRegistry", function() {
       var noop5 = createNoop();
 
       var parent = {
-        notSpied1: noop1
+        parentSpied1: noop1
       };
       var subject = Object.create(parent);
       Object.defineProperty(subject, 'spied1', {
@@ -291,7 +291,7 @@ describe("SpyRegistry", function() {
 
       var spiedObject = spyRegistry.spyOnAllFunctions(subject);
 
-      expect(subject.notSpied1).toBe(noop1);
+      expect(subject.parentSpied1).toBe('I am a spy');
       expect(subject.notSpied2).toBe(noop2);
       expect(subject.notSpied3).toBe(noop3);
       expect(subject.notSpied4).toBe(noop4);
@@ -303,6 +303,42 @@ describe("SpyRegistry", function() {
       expect(subject.spied4).toBe('I am a spy');
       expect(spiedObject).toBe(subject);
     });
+
+    it("overrides prototype methods on the object", function() {
+      var spyRegistry = new jasmineUnderTest.SpyRegistry({createSpy: function() {
+        return 'I am a spy';
+      }});
+
+      var noop1 = function() { };
+      var noop2 = function() { };
+
+      var MyClass = function() {
+        this.spied1 = noop1;
+      };
+      MyClass.prototype.spied2 = noop2;
+
+      var subject = new MyClass();
+      spyRegistry.spyOnAllFunctions(subject);
+
+      expect(subject.spied1).toBe('I am a spy');
+      expect(subject.spied2).toBe('I am a spy');
+      expect(MyClass.prototype.spied2).toBe(noop2);
+    });
+
+    it("does not override non-enumerable properties (like Object.prototype methods)", function() {
+      var spyRegistry = new jasmineUnderTest.SpyRegistry({createSpy: function() {
+        return 'I am a spy';
+      }});
+      var subject = {
+        spied1: function() { }
+      };
+
+      spyRegistry.spyOnAllFunctions(subject);
+
+      expect(subject.spied1).toBe('I am a spy');
+      expect(subject.toString).not.toBe('I am a spy');
+      expect(subject.hasOwnProperty).not.toBe('I am a spy');
+    });
   });
 
   describe("#clearSpies", function() {
diff --git a/src/core/SpyRegistry.js b/src/core/SpyRegistry.js
index 17fd1971..595ce461 100644
--- a/src/core/SpyRegistry.js
+++ b/src/core/SpyRegistry.js
@@ -125,13 +125,25 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
         throw new Error('spyOnAllFunctions could not find an object to spy upon');
       }
 
-      for (var prop in obj) {
-        if (Object.prototype.hasOwnProperty.call(obj, prop) && obj[prop] instanceof Function) {
-          var descriptor = Object.getOwnPropertyDescriptor(obj, prop);
-          if ((descriptor.writable || descriptor.set) && descriptor.configurable) {
-            this.spyOn(obj, prop);
+      var pointer = obj,
+          props = [],
+          prop,
+          descriptor;
+
+      while (pointer) {
+        for (prop in pointer) {
+          if (Object.prototype.hasOwnProperty.call(pointer, prop) && pointer[prop] instanceof Function) {
+            descriptor = Object.getOwnPropertyDescriptor(pointer, prop);
+            if ((descriptor.writable || descriptor.set) && descriptor.configurable) {
+              props.push(prop);
+            }
           }
         }
+        pointer = Object.getPrototypeOf(pointer);
+      }
+
+      for (var i = 0; i < props.length; i++) {
+        this.spyOn(obj, props[i]);
       }
 
       return obj;