diff --git a/tests/unit/core/selector.js b/tests/unit/core/selector.js
index 6d867f634..61f4a2381 100644
--- a/tests/unit/core/selector.js
+++ b/tests/unit/core/selector.js
@@ -3,7 +3,6 @@ define( [
 	"jquery",
 	"lib/helper",
 	"ui/data",
-	"ui/escape-selector",
 	"ui/focusable",
 	"ui/tabbable"
 ], function( QUnit, $, helper ) {
@@ -280,11 +279,4 @@ QUnit.test( "tabbable - dimensionless parent with overflow", function( assert )
 	assert.isTabbable( "#dimensionlessParent", "input" );
 } );
 
-QUnit.test( "escapeSelector", function( assert ) {
-	assert.expect( 1 );
-
-	assert.equal( $( "#" + $.ui.escapeSelector( "weird-['x']-id" ) ).length, 1,
-		"properly escapes selectors to use as an id" );
-} );
-
 } );
diff --git a/ui/escape-selector.js b/ui/escape-selector.js
deleted file mode 100644
index d43e4f816..000000000
--- a/ui/escape-selector.js
+++ /dev/null
@@ -1,21 +0,0 @@
-( function( factory ) {
-	if ( typeof define === "function" && define.amd ) {
-
-		// AMD. Register as an anonymous module.
-		define( [ "jquery", "./version" ], factory );
-	} else {
-
-		// Browser globals
-		factory( jQuery );
-	}
-} ( function( $ ) {
-
-// Internal use only
-return $.ui.escapeSelector = ( function() {
-	var selectorEscape = /([!"#$%&'()*+,./:;<=>?@[\]^`{|}~])/g;
-	return function( selector ) {
-		return selector.replace( selectorEscape, "\\$1" );
-	};
-} )();
-
-} ) );
diff --git a/ui/jquery-patch.js b/ui/jquery-patch.js
index 4d939535e..578c47a3f 100644
--- a/ui/jquery-patch.js
+++ b/ui/jquery-patch.js
@@ -36,6 +36,36 @@ if ( !$.uniqueSort ) {
 	$.uniqueSort = $.unique;
 }
 
+// Support: jQuery 2.2.x or older.
+// This method has been defined in jQuery 3.0.0.
+// Code from https://github.com/jquery/jquery/blob/e539bac79e666bba95bba86d690b4e609dca2286/src/selector/escapeSelector.js
+if ( !$.escapeSelector ) {
+
+	// CSS string/identifier serialization
+	// https://drafts.csswg.org/cssom/#common-serializing-idioms
+	var rcssescape = /([\0-\x1f\x7f]|^-?\d)|^-$|[^\x80-\uFFFF\w-]/g;
+
+	var fcssescape = function( ch, asCodePoint ) {
+		if ( asCodePoint ) {
+
+			// U+0000 NULL becomes U+FFFD REPLACEMENT CHARACTER
+			if ( ch === "\0" ) {
+				return "\uFFFD";
+			}
+
+			// Control characters and (dependent upon position) numbers get escaped as code points
+			return ch.slice( 0, -1 ) + "\\" + ch.charCodeAt( ch.length - 1 ).toString( 16 ) + " ";
+		}
+
+		// Other potentially-special ASCII characters get backslash-escaped
+		return "\\" + ch;
+	};
+
+	$.escapeSelector = function( sel ) {
+		return ( sel + "" ).replace( rcssescape, fcssescape );
+	};
+}
+
 // Support: jQuery 3.4.x or older
 // These methods have been defined in jQuery 3.5.0.
 if ( !$.fn.even || !$.fn.odd ) {
diff --git a/ui/labels.js b/ui/labels.js
index 1bf56ac41..216c46a9a 100644
--- a/ui/labels.js
+++ b/ui/labels.js
@@ -16,7 +16,7 @@
 	if ( typeof define === "function" && define.amd ) {
 
 		// AMD. Register as an anonymous module.
-		define( [ "jquery", "./version", "./escape-selector" ], factory );
+		define( [ "jquery", "./version" ], factory );
 	} else {
 
 		// Browser globals
@@ -53,7 +53,7 @@ return $.fn.labels = function() {
 		ancestors = ancestor.add( ancestor.length ? ancestor.siblings() : this.siblings() );
 
 		// Create a selector for the label based on the id
-		selector = "label[for='" + $.ui.escapeSelector( id ) + "']";
+		selector = "label[for='" + $.escapeSelector( id ) + "']";
 
 		labels = labels.add( ancestors.find( selector ).addBack( selector ) );
 
diff --git a/ui/widgets/checkboxradio.js b/ui/widgets/checkboxradio.js
index 228c9fab9..0cb1a0cf8 100644
--- a/ui/widgets/checkboxradio.js
+++ b/ui/widgets/checkboxradio.js
@@ -23,7 +23,6 @@
 		// AMD. Register as an anonymous module.
 		define( [
 			"jquery",
-			"../escape-selector",
 			"../form-reset-mixin",
 			"../labels",
 			"../widget"
@@ -149,7 +148,7 @@ $.widget( "ui.checkboxradio", [ $.ui.formResetMixin, {
 	_getRadioGroup: function() {
 		var group;
 		var name = this.element[ 0 ].name;
-		var nameSelector = "input[name='" + $.ui.escapeSelector( name ) + "']";
+		var nameSelector = "input[name='" + $.escapeSelector( name ) + "']";
 
 		if ( !name ) {
 			return $( [] );
diff --git a/ui/widgets/selectmenu.js b/ui/widgets/selectmenu.js
index 79e97816b..cc98ecbbf 100644
--- a/ui/widgets/selectmenu.js
+++ b/ui/widgets/selectmenu.js
@@ -25,7 +25,6 @@
 		define( [
 			"jquery",
 			"./menu",
-			"../escape-selector",
 			"../form-reset-mixin",
 			"../keycode",
 			"../labels",
@@ -425,7 +424,7 @@ return $.widget( "ui.selectmenu", [ $.ui.formResetMixin, {
 			}
 
 			if ( !$( event.target ).closest( ".ui-selectmenu-menu, #" +
-					$.ui.escapeSelector( this.ids.button ) ).length ) {
+				$.escapeSelector( this.ids.button ) ).length ) {
 				this.close( event );
 			}
 		}
diff --git a/ui/widgets/tabs.js b/ui/widgets/tabs.js
index 0eb69ebe1..7a53767dd 100644
--- a/ui/widgets/tabs.js
+++ b/ui/widgets/tabs.js
@@ -22,7 +22,6 @@
 		// AMD. Register as an anonymous module.
 		define( [
 			"jquery",
-			"../escape-selector",
 			"../keycode",
 			"../safe-active-element",
 			"../unique-id",
@@ -733,7 +732,7 @@ $.widget( "ui.tabs", {
 		// meta-function to give users option to provide a href string instead of a numerical index.
 		if ( typeof index === "string" ) {
 			index = this.anchors.index( this.anchors.filter( "[href$='" +
-				$.ui.escapeSelector( index ) + "']" ) );
+				$.escapeSelector( index ) + "']" ) );
 		}
 
 		return index;