diff --git a/lib/util.js b/lib/util.js
index 9ead1dd..edb446e 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -142,6 +142,12 @@ exports.propParse = function( data, options )
     // dealing with (in the classic OO sense)
     for ( prop in data )
     {
+        // ignore properties of instance prototypes
+        if ( !( data.hasOwnProperty( prop ) ) )
+        {
+            continue;
+        }
+
         var value = data[ prop ],
             getter = ( ( getset ) ? data.__lookupGetter__( prop ) : null ),
             setter = ( ( getset ) ? data.__lookupSetter__( prop ) : null );
diff --git a/test/test-util-prop-parse.js b/test/test-util-prop-parse.js
index 9e554e0..d380477 100644
--- a/test/test-util-prop-parse.js
+++ b/test/test-util-prop-parse.js
@@ -146,3 +146,24 @@ assert.equal(
     "Property parser supports passing each property to the provided function"
 );
 
+
+var Foo = function() {};
+Foo.prototype.one = 1;
+
+var instance = new Foo();
+instance.two = 2;
+
+var count = 0;
+util.propParse( instance, {
+    each: function()
+    {
+        count++;
+    },
+} );
+
+assert.equal(
+    count,
+    1,
+    "propParse should ignore prototype properties of instances"
+);
+