diff --git a/src/core.js b/src/core.js
index efb16830..67429f77 100644
--- a/src/core.js
+++ b/src/core.js
@@ -936,20 +936,15 @@ jQuery.extend({
 	},
 
 	// Check if an object is a deferred
-	isDeferred: function( object , method ) {
-		method = method || "then";
-		return !!( object && object[ method ] && object[ method ]._ === deferredMarker );
+	isDeferred: function( object ) {
+		return !!( object && object.then && object.then._ === deferredMarker );
 	},
 	
 	// Deferred helper
-	when: function( object , method ) {
-		method = method || "then";
-		object = jQuery.isDeferred( object , method ) ?
+	when: function( object ) {
+		object = jQuery.isDeferred( object ) ?
 			object :
 			jQuery.Deferred().resolve( object );
-		object.fail = object.fail || function() { return this; };
-		object[ method ] = object[ method ] || object.then;
-		object.then = object.then || object[ method ];
 		return object;
 	},
 
diff --git a/test/unit/core.js b/test/unit/core.js
index 19670074..e0938b68 100644
--- a/test/unit/core.js
+++ b/test/unit/core.js
@@ -1024,7 +1024,7 @@ test("jQuery.Deferred()", function() {
 	
 test("jQuery.isDeferred()", function() {
 	
-	expect( 11 );
+	expect( 10 );
 	
 	var object1 = { then: function() { return this; } },
 		object2 = { then: function() { return this; } };
@@ -1049,14 +1049,13 @@ test("jQuery.isDeferred()", function() {
 	object1 = {custom: jQuery._Deferred().then};
 	
 	ok(!jQuery.isDeferred(object1) , "custom method name not found automagically");
-	ok(jQuery.isDeferred(object1,"custom") , "custom method name");
 });
 
 test("jQuery.when()", function() {
 	
-	expect( 5 );
+	expect( 2 );
 	
-	var cache, i, deferred = { done: jQuery.Deferred().resolve( 1 ).then };
+	var cache, i;
 	
 	for( i = 1 ; i < 3 ; i++ ) {
 		jQuery.when( cache || jQuery.Deferred( function() {
@@ -1068,22 +1067,4 @@ test("jQuery.when()", function() {
 			ok( false , "Fail called" );
 		});
 	}
-	
-	cache = 0;
-
-	for( i = 1 ; i < 3 ; i++ ) {
-		jQuery.when( cache || deferred , "done" ).done( function( value ) {
-			strictEqual( value , 1 , "Custom method: resolved" + ( i > 1 ? " only once" : "" ) );
-			cache = value;
-		}).fail( function() {
-			ok( false , "Custom method: fail called" );
-		});
-	}
-	
-	stop();
-	
-	jQuery.when( jQuery( document ) , "ready" ).then( function( test ) {
-		strictEqual( test , jQuery , "jQuery.fn.ready recognized as a deferred" );
-		start();
-	});
 });