diff --git a/src/ajax.js b/src/ajax.js
index 77537e706..4b84538df 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -291,11 +291,8 @@ jQuery.extend({
 		} catch(e){}
 
 		// Allow custom headers/mimetypes
-		if ( s.beforeSend )
-			var beforeSendSuccess = s.beforeSend(xml, s);
-			
-		if( beforeSendSuccess === false )
-		  return false;
+		if ( s.beforeSend && s.beforeSend(xml, s) === false )
+			return false;
 		
 		if ( s.global )
 			jQuery.event.trigger("ajaxSend", [xml, s]);
diff --git a/test/unit/ajax.js b/test/unit/ajax.js
index 15c4ed744..c6557f4ed 100644
--- a/test/unit/ajax.js
+++ b/test/unit/ajax.js
@@ -136,6 +136,27 @@ test("$.ajax - beforeSend", function() {
 	});
 });
 
+test("$.ajax - beforeSend, cancel request (#2688)", function() {
+	expect(2);
+	var request = $.ajax({
+		url: url("data/name.html"), 
+		beforeSend: function() {
+			ok( true, "beforeSend got called, canceling" );
+			return false;
+		},
+		success: function() {
+			ok( false, "request didn't get canceled" );
+		},
+		complete: function() {
+			ok( false, "request didn't get canceled" );
+		},
+		error: function() {
+			ok( false, "request didn't get canceled" );
+		}
+	});
+	ok( request === false, "canceled request must return false instead of XMLHttpRequest instance" );
+});
+
 var foobar;
 
 test("$.ajax - dataType html", function() {