diff --git a/object.js b/object.js
index 7e7dfb7..8cb7d6b 100644
--- a/object.js
+++ b/object.js
@@ -120,16 +120,22 @@ define(function (require) {
 		'object-isextensible': 'isExtensible',
 		'object-preventextensions': 'preventExtensions',
 		'object-defineproperty-obj': function () {
-			return hasDefineProperty({});
+			return hasDefineProperty({}, 'sentinel1', { value: true });
 		},
 		'object-defineproperty-dom': function () {
-			return doc && hasDefineProperty(testEl);
+			return doc && hasDefineProperty(testEl, 'sentinel1', { value: true });
+		},
+		'object-defineproperty-function': function () {
+			return hasDefineProperty(function () {}, 'prototype', { value: { test: true } });
 		},
 		'object-defineproperties-obj': function () {
-			return hasDefineProperties({});
+			return hasDefineProperties({}, { 'sentinel2': { value: true } });
 		},
 		'object-defineproperties-dom': function () {
-			return doc && hasDefineProperties(testEl);
+			return doc && hasDefineProperties(testEl, { 'sentinel2': { value: true } });
+		},
+		'object-defineproperties-function': function () {
+			return hasDefineProperties(function () {}, { 'prototype': { value: { test: true } } });
 		},
 		'object-getownpropertydescriptor-obj': function () {
 			return hasGetOwnPropertyDescriptor({});
@@ -196,6 +202,13 @@ define(function (require) {
 				? useNativeForDom(Object.defineProperties, defineProperties)
 				: defineProperties;
 	}
+	else {
+		// check if it can assign a value to a function's prototype
+		if (!has('object-defineproperties-function')) {
+			Object.defineProperties = shims.defineProperties
+				= definePropertiesFunctionPrototype(Object.defineProperties, defineProperties);
+		}
+	}
 
 	if (!has('object-defineproperty-obj')) {
 		// check if dom has it (IE8)
@@ -204,6 +217,13 @@ define(function (require) {
 				? useNativeForDom(Object.defineProperty, defineProperty)
 				: defineProperty;
 	}
+	else {
+		// check if it can assign a value to a function's prototype
+		if (!has('object-defineproperty-function')) {
+			Object.defineProperty = shims.defineProperty
+				= definePropertyFunctionPrototype(Object.defineProperty, defineProperty);
+		}
+	}
 
 	if (!has('object-isextensible')) {
 		Object.isExtensible = shims.isExtensible = isExtensible;
@@ -221,12 +241,12 @@ define(function (require) {
 				: getOwnPropertyDescriptor;
 	}
 
-	function hasDefineProperty (object) {
+	function hasDefineProperty (object, prop, descriptor) {
 		if (('defineProperty' in Object)) {
 			try {
 				// test it
-				Object.defineProperty(object, 'sentinel1', { value: true })
-				return object['sentinel1'] === true;
+				Object.defineProperty(object, prop, descriptor);
+				return object[prop] === descriptor.value;
 			}
 			catch (ex) { /* squelch */ }
 		}
@@ -234,12 +254,21 @@ define(function (require) {
 
 	// Note: MSDN docs say that IE8 has this function, but tests show
 	// that it does not! JMH
-	function hasDefineProperties (object) {
+	function hasDefineProperties (object, props) {
+		var keys, property;
+
 		if (('defineProperties' in Object)) {
 			try {
 				// test it
-				Object.defineProperties(object, { 'sentinel2': { value: true } })
-				return object['sentinel2'] === true;
+				Object.defineProperties(object, props);
+				keys = _keys(props);
+
+				while (property = keys.pop()) {
+					if (object[property] !== props[property].value) {
+						return false;
+					}
+				}
+				return true;
 			}
 			catch (ex) { /* squelch */ }
 		}
@@ -308,11 +337,27 @@ define(function (require) {
 		return object;
 	}
 
+	function definePropertiesFunctionPrototype (orig, shim) {
+		return function (object, descriptors) {
+			return (!!descriptors['prototype'] && typeof object === 'function')
+				? shim.apply(this, arguments)	// use shim
+				: orig.apply(this, arguments);	// use native
+		};
+	}
+
 	function defineProperty (object, name, descriptor) {
 		object[name] = descriptor && descriptor.value;
 		return object;
 	}
 
+	function definePropertyFunctionPrototype (orig, shim) {
+		return function (object, name, descriptor) {
+			return (name === 'prototype' && typeof object === 'function')
+				? shim.apply(this, arguments)	// use shim
+				: orig.apply(this, arguments);	// use native
+		};
+	}
+
 	function getOwnPropertyDescriptor (object, name) {
 		return hasProp(object, name)
 			? {
diff --git a/test/object.html b/test/object.html
index 2e36943..8d3dbef 100644
--- a/test/object.html
+++ b/test/object.html
@@ -258,6 +258,13 @@
 			Object.defineProperty(test, 'foo', { value: 5 });
 			return test.foo == 5;
 		});
+		tester.assertTrue("Object.defineProperty should define the prototype property correctly", function () {
+			function fn() {};
+
+			Object.defineProperty(fn, 'prototype', { value: { test: true } });
+
+			return fn.prototype.test === true && (new fn).test === true;
+		});
 		tester.assertTrue('Object.defineProperties should add several properties', function () {
 			var test = {};
 			// writable and get don't actually work, just putting them in here
@@ -267,6 +274,18 @@
 			});
 			return test.foo == 5 && test.bar == 27;
 		});
+		tester.assertTrue("Object.defineProperties should define the prototype property correctly", function () {
+			function fn() {};
+
+			Object.defineProperties(fn, {
+				prototype: {
+					value: {
+						test: true
+					}
+				}
+			});
+			return fn.prototype.test === true && (new fn).test === true;
+		});
 
 		// test getOwnPropertyDescriptor
 		tester.assertTrue('Object.getOwnPropertyDescriptor should return a factual descriptor object', function () {