diff --git a/boot/boot.js b/boot/boot.js
index 6e99863f8..ba780a109 100644
--- a/boot/boot.js
+++ b/boot/boot.js
@@ -2467,16 +2467,29 @@ $tw.boot.executeNextStartupTask = function(callback) {
 };
 
 /*
-Returns true if we are running on one platforms specified in a task modules `platforms` array
+Returns true if we are running on one of the platforms specified in taskModule's
+`platforms` array; or if `platforms` property is not defined.
 */
 $tw.boot.doesTaskMatchPlatform = function(taskModule) {
 	var platforms = taskModule.platforms;
 	if(platforms) {
 		for(var t=0; t<platforms.length; t++) {
-			if((platforms[t] === "browser" && !$tw.browser) || (platforms[t] === "node" && !$tw.node)) {
-				return false;
+			switch (platforms[t]) {
+				case "browser":
+					if ($tw.browser) {
+						return true;
+					}
+					break;
+				case "node":
+					if ($tw.node) {
+						return true;
+					}
+					break;
+				default:
+					$tw.utils.error("Module " + taskModule.name + ": '" + platforms[t] + "' in export.platforms invalid");
 			}
 		}
+		return false;
 	}
 	return true;
 };
diff --git a/core/modules/filters/encodings.js b/core/modules/filters/encodings.js
index 557599c1a..a41086604 100644
--- a/core/modules/filters/encodings.js
+++ b/core/modules/filters/encodings.js
@@ -102,7 +102,7 @@ exports.escapecss = function(source,operator,options) {
 	var results = [];
 	source(function(tiddler,title) {
 		// escape any character with a special meaning in CSS using CSS.escape()
-		results.push(CSS.escape(title));
+		results.push($tw.utils.escapeCSS(title));
 	});
 	return results;
 };
diff --git a/core/modules/startup/css-escape-polyfill.js b/core/modules/utils/escapecss.js
similarity index 75%
rename from core/modules/startup/css-escape-polyfill.js
rename to core/modules/utils/escapecss.js
index dfc904f89..5935b034a 100644
--- a/core/modules/startup/css-escape-polyfill.js
+++ b/core/modules/utils/escapecss.js
@@ -1,33 +1,28 @@
 /*\
-title: $:/core/modules/startup/CSSescape.js
+title: $:/core/modules/utils/escapecss.js
 type: application/javascript
-module-type: startup
+module-type: utils
 
-Polyfill for CSS.escape()
+Provides CSS.escape() functionality.
 
 \*/
-(function(root,factory){
+(function(){
+
 /*jslint node: true, browser: true */
-/*global $tw: false */
+/*global $tw: false, window: false */
 "use strict";
 
-// Export name and synchronous status
-exports.name = "css-escape";
-exports.platforms = ["browser"];
-exports.after = ["startup"];
-exports.synchronous = true;
-
-/*! https://mths.be/cssescape v1.5.1 by @mathias | MIT license */
-// https://github.com/umdjs/umd/blob/master/returnExports.js
-exports.startup = function() {factory(root);}; 
-}(typeof global != 'undefined' ? global : this, function(root) {
-
-	if (root.CSS && root.CSS.escape) {
-		return;
+exports.escapeCSS = (function() {
+	// use browser's native CSS.escape() function if available
+	if ($tw.browser && window.CSS && window.CSS.escape) {
+		return window.CSS.escape;
 	}
 
-	// https://drafts.csswg.org/cssom/#serialize-an-identifier
-	var cssEscape = function(value) {
+	// otherwise, a utility method is provided
+	// see also https://drafts.csswg.org/cssom/#serialize-an-identifier
+
+	/*! https://mths.be/cssescape v1.5.1 by @mathias | MIT license */
+	return function(value) {
 		if (arguments.length == 0) {
 			throw new TypeError('`CSS.escape` requires an argument.');
 		}
@@ -104,11 +99,6 @@ exports.startup = function() {factory(root);};
 		}
 		return result;
 	};
+})();
 
-	if (!root.CSS) {
-		root.CSS = {};
-	}
-
-	Object.getPrototypeOf(root.CSS).escape = cssEscape;
-
-}));
+})();
diff --git a/editions/test/tiddlers/tests/test-filters.js b/editions/test/tiddlers/tests/test-filters.js
index b67a2d298..ca184a40d 100644
--- a/editions/test/tiddlers/tests/test-filters.js
+++ b/editions/test/tiddlers/tests/test-filters.js
@@ -796,6 +796,17 @@ function runTests(wiki) {
 	expect(wiki.filterTiddlers("[[12]pad[9],[abc]]").join(",")).toBe("abcabca12");
 	expect(wiki.filterTiddlers("[[12]pad:suffix[9],[abc]]").join(",")).toBe("12abcabca");
 	});
+
+	it("should handle the escapecss operator", function() {
+	expect(wiki.filterTiddlers("[[Hello There]escapecss[]]").join(",")).toBe("Hello\\ There");
+	expect(wiki.filterTiddlers('\'"Reveal.js" by Devin Weaver[1]\' +[escapecss[]]').join(",")).toBe('\\"Reveal\\.js\\"\\ by\\ Devin\\ Weaver\\[1\\]');
+	expect(wiki.filterTiddlers(".foo#bar (){} '--a' 0 \0 +[escapecss[]]").join(",")).toBe("\\.foo\\#bar,\\(\\)\\{\\},--a,\\30 ,\ufffd");
+	expect(wiki.filterTiddlers("'' +[escapecss[]]").join(",")).toBe("");
+	expect(wiki.filterTiddlers("1234 +[escapecss[]]").join(",")).toBe("\\31 234");
+	expect(wiki.filterTiddlers("'-25' +[escapecss[]]").join(",")).toBe("-\\32 5");
+	expect(wiki.filterTiddlers("'-' +[escapecss[]]").join(",")).toBe("\\-");
+	});
+
 }
 
 });