diff --git a/chai-spies.js b/chai-spies.js
index 2e48cca..f58bdfb 100644
--- a/chai-spies.js
+++ b/chai-spies.js
@@ -87,7 +87,7 @@
         object: object
         , methodName: methodName
         , originalMethod: object[methodName]
-        , isOwnMethod: object.hasOwnProperty(methodName)
+        , isOwnMethod: Object.hasOwnProperty.call(object, methodName)
       };
       object[methodName] = method;
 
diff --git a/lib/spy.js b/lib/spy.js
index 97285c9..b3eb0e6 100644
--- a/lib/spy.js
+++ b/lib/spy.js
@@ -81,7 +81,7 @@ module.exports = function (chai, _) {
       object: object
       , methodName: methodName
       , originalMethod: object[methodName]
-      , isOwnMethod: object.hasOwnProperty(methodName)
+      , isOwnMethod: Object.hasOwnProperty.call(object, methodName)
     };
     object[methodName] = method;
 
diff --git a/test/spies.js b/test/spies.js
index 7ec93da..ab4acf8 100644
--- a/test/spies.js
+++ b/test/spies.js
@@ -609,6 +609,16 @@ describe('Chai Spies', function () {
       object.push().should.equal(5);
       object.pop().should.equal(5);
     })
+
+    it('should work with a nullish prototype', function() {
+      var nullish = Object.create(null);
+      nullish.method = function() {
+        return 1;
+      };
+      chai.spy.on(nullish, 'method');
+      nullish.method().should.equal(1);
+    });
+
   });
 
   describe('spy interface', function () {