diff --git a/tests/unit/core/selector.js b/tests/unit/core/selector.js
index dee24809e..e553e769d 100644
--- a/tests/unit/core/selector.js
+++ b/tests/unit/core/selector.js
@@ -1,8 +1,9 @@
 define( [
 	"jquery",
-	"ui/core",
 	"ui/data",
-	"ui/focusable"
+	"ui/escape-selector",
+	"ui/focusable",
+	"ui/tabbable"
 ], function( $ ) {
 
 module( "core - selectors" );
diff --git a/ui/core.js b/ui/core.js
index 9e799a04c..d443346e8 100644
--- a/ui/core.js
+++ b/ui/core.js
@@ -31,6 +31,7 @@
 			"./plugin",
 			"./safe-active-element",
 			"./safe-blur",
+			"./tabbable",
 			"./version"
 		], factory );
 	} else {
@@ -78,12 +79,4 @@ $.fn.extend( {
 	}
 } );
 
-$.extend( $.expr[ ":" ], {
-	tabbable: function( element ) {
-		var tabIndex = $.attr( element, "tabindex" ),
-			hasTabindex = tabIndex != null;
-		return ( !hasTabindex || tabIndex >= 0 ) && $.ui.focusable( element, hasTabindex );
-	}
-} );
-
 } ) );
diff --git a/ui/dialog.js b/ui/dialog.js
index acb7814d1..16d650f97 100644
--- a/ui/dialog.js
+++ b/ui/dialog.js
@@ -32,7 +32,8 @@
 			"./position",
 			"./resizable",
 			"./safe-active-element",
-			"./safe-blur"
+			"./safe-blur",
+			"./tabbable"
 		], factory );
 	} else {
 
diff --git a/ui/tabbable.js b/ui/tabbable.js
new file mode 100644
index 000000000..86bebb77b
--- /dev/null
+++ b/ui/tabbable.js
@@ -0,0 +1,35 @@
+/*!
+ * jQuery UI Tabbable @VERSION
+ * http://jqueryui.com
+ *
+ * Copyright jQuery Foundation and other contributors
+ * Released under the MIT license.
+ * http://jquery.org/license
+ */
+
+//>>label: focusable
+//>>group: Core
+//>>description: Selects elements which can be tabbed to.
+//>>docs: http://api.jqueryui.com/tabbable-selector/
+
+( function( factory ) {
+	if ( typeof define === "function" && define.amd ) {
+
+		// AMD. Register as an anonymous module.
+		define( [ "jquery", "./version", "./focusable" ], factory );
+	} else {
+
+		// Browser globals
+		factory( jQuery );
+	}
+} ( function( $ ) {
+
+return $.extend( $.expr[ ":" ], {
+	tabbable: function( element ) {
+		var tabIndex = $.attr( element, "tabindex" ),
+			hasTabindex = tabIndex != null;
+		return ( !hasTabindex || tabIndex >= 0 ) && $.ui.focusable( element, hasTabindex );
+	}
+} );
+
+} ) );