diff --git a/lib/jasmine-core/jasmine.js b/lib/jasmine-core/jasmine.js
index 4761f6f9..e0516c74 100644
--- a/lib/jasmine-core/jasmine.js
+++ b/lib/jasmine-core/jasmine.js
@@ -510,23 +510,23 @@ jasmine.util.extend = function(destination, source) {
 
 //TODO: expectation result may make more sense as a presentation of an expectation.
 jasmine.ExpectationResult = function(params) {
-  this.type = 'expect';
-  this.matcherName = params.matcherName;
-  this.passed_ = params.passed;
-  this.expected = params.expected;
-  this.actual = params.actual;
-  this.message = this.passed_ ? 'Passed.' : params.message;
-
+  var self = this;
   var trace = (params.trace || new Error(this.message));
-  this.trace = this.passed_ ? '' : trace;
-};
-
-jasmine.ExpectationResult.prototype.toString = function () {
-  return this.message;
-};
-
-jasmine.ExpectationResult.prototype.passed = function () {
-  return this.passed_;
+  var message = params.passed ? 'Passed.' : params.message;
+  return jasmine.util.extend(self, {
+    type: 'expect',
+    matcherName: params.matcherName,
+    expected: params.expected,
+    actual:  params.actual,
+    message: message,
+    trace: params.passed ? '' : trace,
+    toString: function() {
+      return message;
+    },
+    passed: function() {
+      return params.passed;
+    }
+  });
 };
 /**
  * Environment for Jasmine
diff --git a/spec/core/CustomMatchersSpec.js b/spec/core/CustomMatchersSpec.js
index 86f98547..55c52067 100644
--- a/spec/core/CustomMatchersSpec.js
+++ b/spec/core/CustomMatchersSpec.js
@@ -61,12 +61,10 @@ describe("Custom Matchers", function() {
     });
 
     suite.execute();
-    var passResult = new jasmine.ExpectationResult({passed: true, matcherName: 'toBeTrue',
-      actual: true, expected: jasmine.undefined, message: "Passed." });
-    var failResult = new jasmine.ExpectationResult({passed: false, matcherName: 'toBeTrue',
-      actual: false, expected: jasmine.undefined, message: "Expected false to be true." });
-    failResult.trace = originalJasmine.any(Object);
-    expect(spec.results().getItems()).toEqual([passResult, failResult]);
+
+    var results = spec.results().getItems();
+    expect(results[0].message).toEqual("Passed.");
+    expect(results[1].message).toEqual("Expected false to be true.");
   });
 
   it("should pass args", function() {
diff --git a/spec/core/ExpectationResultSpec.js b/spec/core/ExpectationResultSpec.js
index b84b1f97..03f52036 100644
--- a/spec/core/ExpectationResultSpec.js
+++ b/spec/core/ExpectationResultSpec.js
@@ -5,11 +5,16 @@ describe("ExpectationResult", function() {
     expect(result.passed()).toBe('some-value');
   });
 
-  it("#toString returns message", function() {
-    var result = new jasmine.ExpectationResult({message: 'some-value'});
+  it("#toString returns message when failing", function() {
+    var result = new jasmine.ExpectationResult({passed: false, message: 'some-value'});
     expect(result.toString()).toBe('some-value');
   });
 
+  it("#toString returns Passed when passing", function() {
+    var result = new jasmine.ExpectationResult({passed: true, message: 'some-value'});
+    expect(result.toString()).toBe('Passed.');
+  });
+
   it("has a type of expect", function() {
     var result = new jasmine.ExpectationResult({});
     expect(result.type).toBe('expect');
diff --git a/spec/node_suite.js b/spec/node_suite.js
index bd2867b3..7bd9c480 100644
--- a/spec/node_suite.js
+++ b/spec/node_suite.js
@@ -110,7 +110,7 @@ process.argv.forEach(function(arg) {
   }
 });
 
-var specs = jasmine.getAllSpecFiles(__dirname, new RegExp(".js$"));
+var specs = jasmine.getAllSpecFiles(__dirname, new RegExp("Spec.js$"));
 var domIndependentSpecs = [];
 for (var i = 0; i < specs.length; i++) {
   if (fs.readFileSync(specs[i], "utf8").indexOf("document.createElement") < 0) {
diff --git a/src/core/ExpectationResult.js b/src/core/ExpectationResult.js
index 9c49cbc5..b33dd01a 100644
--- a/src/core/ExpectationResult.js
+++ b/src/core/ExpectationResult.js
@@ -1,20 +1,20 @@
 //TODO: expectation result may make more sense as a presentation of an expectation.
 jasmine.ExpectationResult = function(params) {
-  this.type = 'expect';
-  this.matcherName = params.matcherName;
-  this.passed_ = params.passed;
-  this.expected = params.expected;
-  this.actual = params.actual;
-  this.message = this.passed_ ? 'Passed.' : params.message;
-
+  var self = this;
   var trace = (params.trace || new Error(this.message));
-  this.trace = this.passed_ ? '' : trace;
-};
-
-jasmine.ExpectationResult.prototype.toString = function () {
-  return this.message;
-};
-
-jasmine.ExpectationResult.prototype.passed = function () {
-  return this.passed_;
+  var message = params.passed ? 'Passed.' : params.message;
+  return jasmine.util.extend(self, {
+    type: 'expect',
+    matcherName: params.matcherName,
+    expected: params.expected,
+    actual:  params.actual,
+    message: message,
+    trace: params.passed ? '' : trace,
+    toString: function() {
+      return message;
+    },
+    passed: function() {
+      return params.passed;
+    }
+  });
 };