diff --git a/spec/suites/EnvSpec.js b/spec/suites/EnvSpec.js
index 7da6ee0..e907834 100644
--- a/spec/suites/EnvSpec.js
+++ b/spec/suites/EnvSpec.js
@@ -65,4 +65,77 @@ describe("jasmine.Env", function() {
       expect(fakeReporter.log).wasCalledWith("message");
     });
   });
+
+  describe("equality testing", function() {
+    describe("with custom equality testers", function() {
+      var aObj, bObj, isEqual;
+
+      beforeEach(function() {
+        env.addEqualityTester(function(a, b) {
+          aObj = a;
+          bObj = b;
+          return isEqual;
+        });
+      });
+
+      it("should call the custom equality tester with two objects for comparison", function() {
+        env.equals_("1", "2");
+        expect(aObj).toEqual("1");
+        expect(bObj).toEqual("2");
+      });
+
+      describe("when the custom equality tester returns false", function() {
+        beforeEach(function() {
+          isEqual = false;
+        });
+
+        it("should give custom equality testers precedence", function() {
+          expect(env.equals_('abc', 'abc')).toBeFalsy();
+          var o = new Object();
+          expect(env.equals_(o, o)).toBeFalsy();
+        });
+      });
+
+
+      describe("when the custom equality tester returns true", function() {
+        beforeEach(function() {
+          isEqual = true;
+        });
+
+        it("should give custom equality testers precedence", function() {
+          expect(env.equals_('abc', 'def')).toBeTruthy();
+          expect(env.equals_(true, false)).toBeTruthy();
+        });
+      });
+
+      describe("when the custom equality tester returns undefined", function() {
+        beforeEach(function() {
+          isEqual = jasmine.undefined;
+        });
+
+        it("should use normal equality rules", function() {
+          expect(env.equals_('abc', 'abc')).toBeTruthy();
+          expect(env.equals_('abc', 'def')).toBeFalsy();
+        });
+
+        describe("even if there are several", function() {
+          beforeEach(function() {
+            env.addEqualityTester(function(a, b) { return jasmine.undefined; });
+            env.addEqualityTester(function(a, b) { return jasmine.undefined; });
+          });
+
+          it("should use normal equality rules", function() {
+            expect(env.equals_('abc', 'abc')).toBeTruthy();
+            expect(env.equals_('abc', 'def')).toBeFalsy();
+          });
+        });
+      });
+
+      it("should evaluate custom equality testers in the order they are declared", function() {
+        isEqual = false;
+        env.addEqualityTester(function(a, b) { return true; });
+        expect(env.equals_('abc', 'abc')).toBeFalsy();
+      });
+    });
+  });
 });
\ No newline at end of file
diff --git a/src/Env.js b/src/Env.js
index 5d288b3..8a50035 100644
--- a/src/Env.js
+++ b/src/Env.js
@@ -181,6 +181,12 @@ jasmine.Env.prototype.equals_ = function(a, b, mismatchKeys, mismatchValues) {
   mismatchKeys = mismatchKeys || [];
   mismatchValues = mismatchValues || [];
 
+  for (var i = 0; i < this.equalityTesters_.length; i++) {
+    var equalityTester = this.equalityTesters_[i];
+    var result = equalityTester(a, b, this, mismatchKeys, mismatchValues);
+    if (result !== jasmine.undefined) return result;
+  }
+
   if (a === b) return true;
 
   if (a === jasmine.undefined || a === null || b === jasmine.undefined || b === null) {
@@ -207,12 +213,6 @@ jasmine.Env.prototype.equals_ = function(a, b, mismatchKeys, mismatchValues) {
     return this.compareObjects_(a, b, mismatchKeys, mismatchValues);
   }
 
-  for (var i = 0; i < this.equalityTesters_.length; i++) {
-    var equalityTester = this.equalityTesters_[i];
-    var result = equalityTester(a, b, this, mismatchKeys, mismatchValues);
-    if (result !== jasmine.undefined) return result;
-  }
-
   //Straight check
   return (a === b);
 };