diff --git a/js/ArgParser.js b/js/ArgParser.js
index 0d892f7d0..f4906e41a 100755
--- a/js/ArgParser.js
+++ b/js/ArgParser.js
@@ -26,7 +26,7 @@ Options and their defaults are:
 /*jslint node: true */
 "use strict";
 
-var Sandbox = require("./Sandbox.js").Sandbox;
+var sandbox = require("./Sandbox.js").sandbox;
 
 var ArgParser = function(argString,options) {
 	var parseToken = function(match,p) {
@@ -38,7 +38,7 @@ var ArgParser = function(argString,options) {
 			} else if(match[p+2]) { // Double-square-bracket quoted
 				n = match[p+2];
 			} else if(match[p+3]) { // Double-brace quoted
-				n = options.allowEval === false ? match[p+3] : Sandbox(match[p+3],options.globals);
+				n = options.allowEval === false ? match[p+3] : sandbox(match[p+3],options.globals);
 			} else if(match[p+4]) { // Unquoted
 				n = match[p+4];
 			} else if(match[p+5]) { // empty quote
diff --git a/js/Sandbox.js b/js/Sandbox.js
index 3cc61eccc..3acab652a 100644
--- a/js/Sandbox.js
+++ b/js/Sandbox.js
@@ -6,16 +6,12 @@ Execute a fragment of JavaScript in a sandbox
 \*/
 (function(){
 
-/*jslint node: true */
+/*jslint evil: true, node: true */
 "use strict";
 
 var uglify = require("uglify-js");
 
-var safeEval = function(e) {
-	return eval(e);
-};
-
-var Sandbox = function(code,globals) {
+var sandbox = function(code,globals) {
 	var globalNames = [],
 		globalValues = [],
 		collectGlobals = function(globals) {
@@ -34,7 +30,7 @@ var Sandbox = function(code,globals) {
 	});
 	// Compose the code
 	var out = [];
-	out.push("(function(")
+	out.push("(function(");
 	out.push(globalNames.join(","));
 	out.push(") { return ");
 	out.push(code);
@@ -45,9 +41,15 @@ var Sandbox = function(code,globals) {
 	// Recompile the code
 	var compiledCode = uglify.uglify.gen_code(tree);
 	// Execute it
-	return eval(compiledCode).apply(null,globalValues);
+	var result;
+	try {
+		result = eval(compiledCode).apply(null,globalValues);
+	} catch(err) {
+		result = "{{** Evaluation error: " + err + " **}}";
+	}
+	return result;
 };
 
-exports.Sandbox = Sandbox;
+exports.sandbox = sandbox;
 
 })();
\ No newline at end of file
diff --git a/test/wikitests/SeventhTiddler.html b/test/wikitests/SeventhTiddler.html
new file mode 100644
index 000000000..c0c644dad
--- /dev/null
+++ b/test/wikitests/SeventhTiddler.html
@@ -0,0 +1 @@
+4<br /><br />SeventhTiddler<br /><br />{{** Evaluation error: ReferenceError: window is not defined **}}<br />
\ No newline at end of file
diff --git a/test/wikitests/SeventhTiddler.tid b/test/wikitests/SeventhTiddler.tid
new file mode 100644
index 000000000..31e3fcf73
--- /dev/null
+++ b/test/wikitests/SeventhTiddler.tid
@@ -0,0 +1,7 @@
+title: SeventhTiddler
+
+<<echo {{2+2}}>>
+
+<<echo {{title}}>>
+
+<<echo {{window}}>>
diff --git a/test/wikitests/SeventhTiddler.txt b/test/wikitests/SeventhTiddler.txt
new file mode 100644
index 000000000..025a2c7e2
--- /dev/null
+++ b/test/wikitests/SeventhTiddler.txt
@@ -0,0 +1 @@
+4SeventhTiddler{{** Evaluation error: ReferenceError: window is not defined **}}
\ No newline at end of file
diff --git a/test/wikitests/SixthTiddler.html b/test/wikitests/SixthTiddler.html
index b9ef11a8d..380190616 100644
--- a/test/wikitests/SixthTiddler.html
+++ b/test/wikitests/SixthTiddler.html
@@ -1 +1 @@
-SixthTiddler<br /><a href="SixthTiddler">SixthTiddler</a><br />11 February 2011<br /><a href="Jermolene">Jermolene</a><br /><ul><li><a href="Fifth Tiddler">Fifth Tiddler</a></li><li><a href="FirstTiddler">FirstTiddler</a></li><li><a href="Fourth Tiddler">Fourth Tiddler</a></li><li><a href="SecondTiddler">SecondTiddler</a></li><li><a href="SixthTiddler">SixthTiddler</a></li><li><a href="ThirdTiddler">ThirdTiddler</a></li></ul><br />
\ No newline at end of file
+SixthTiddler<br /><a href="SixthTiddler">SixthTiddler</a><br />11 February 2011<br /><a href="Jermolene">Jermolene</a><br /><ul><li><a href="Fifth Tiddler">Fifth Tiddler</a></li><li><a href="FirstTiddler">FirstTiddler</a></li><li><a href="Fourth Tiddler">Fourth Tiddler</a></li><li><a href="SecondTiddler">SecondTiddler</a></li><li><a href="SeventhTiddler">SeventhTiddler</a></li><li><a href="SixthTiddler">SixthTiddler</a></li><li><a href="ThirdTiddler">ThirdTiddler</a></li></ul><br />
\ No newline at end of file
diff --git a/test/wikitests/SixthTiddler.txt b/test/wikitests/SixthTiddler.txt
index 8a78b69f9..5d2c17db9 100644
--- a/test/wikitests/SixthTiddler.txt
+++ b/test/wikitests/SixthTiddler.txt
@@ -1 +1 @@
-SixthTiddlerSixthTiddler11 February 2011JermoleneFifth TiddlerFirstTiddlerFourth TiddlerSecondTiddlerSixthTiddlerThirdTiddler
\ No newline at end of file
+SixthTiddlerSixthTiddler11 February 2011JermoleneFifth TiddlerFirstTiddlerFourth TiddlerSecondTiddlerSeventhTiddlerSixthTiddlerThirdTiddler
\ No newline at end of file
diff --git a/wikitest.js b/wikitest.js
index 0e3ed4f82..b472d0d68 100644
--- a/wikitest.js
+++ b/wikitest.js
@@ -59,10 +59,10 @@ for(t=0; t<titles.length; t++) {
 		htmlRender = store.renderTiddler("text/html",titles[t]),
 		plainRender = store.renderTiddler("text/plain",titles[t]);
 	if(htmlTarget !== htmlRender) {
-		console.error("Tiddler %s html error\nTarget: %s\nFound: %s\n",titles[t],htmlTarget,htmlRender);
+		console.error("Tiddler %s html error\nTarget: %s\nFound:  %s\n",titles[t],htmlTarget,htmlRender);
 	}
 	if(plainTarget !== plainRender) {
-		console.error("Tiddler %s plain text error\nTarget: %s\nFound: %s\n",titles[t],plainTarget,plainRender);
+		console.error("Tiddler %s plain text error\nTarget: %s\nFound:  %s\n",titles[t],plainTarget,plainRender);
 	}
 }