diff --git a/chrome/content/zotero/xpcom/translation/translate_firefox.js b/chrome/content/zotero/xpcom/translation/translate_firefox.js
index b68c1d882b..c9cc2acfef 100644
--- a/chrome/content/zotero/xpcom/translation/translate_firefox.js
+++ b/chrome/content/zotero/xpcom/translation/translate_firefox.js
@@ -45,22 +45,17 @@ Zotero.Translate.SandboxManager = function(sandboxLocation) {
 	// import functions missing from global scope into Fx sandbox
 	this.sandbox.XPathResult = Components.interfaces.nsIDOMXPathResult;
 	this.sandbox.DOMParser = function() {
+		var uri, principal;
 		// get URI
-		// DEBUG: In Fx 4 we can just use document.nodePrincipal, but in Fx 3.6 this doesn't work
 		if(typeof sandboxLocation === "string") {	// if sandbox specified by URI
-			var uri = sandboxLocation;
+			var secMan = Services.scriptSecurityManager;
+			uri = Services.io.newURI(sandboxLocation, "UTF-8", null);
+			principal = (secMan.getCodebasePrincipal || secMan.getSimpleCodebasePrincipal)(uri);
 		} else {									// if sandbox specified by DOM document
-			var uri = sandboxLocation.location.toString();
+			principal = sandboxLocation.document.nodePrincipal;
+			uri = sandboxLocation.document.documentURIObject;
 		}
 		
-		// get principal from URI
-		var secMan = Components.classes["@mozilla.org/scriptsecuritymanager;1"]
-				.getService(Components.interfaces.nsIScriptSecurityManager);
-		var ioService = Components.classes["@mozilla.org/network/io-service;1"]
-			.getService(Components.interfaces.nsIIOService);
-		uri = ioService.newURI(uri, "UTF-8", null);
-		var principal = secMan.getCodebasePrincipal(uri);
-		
 		// initialize DOM parser
 		var _DOMParser = Components.classes["@mozilla.org/xmlextras/domparser;1"]
 			.createInstance(Components.interfaces.nsIDOMParser);
@@ -68,12 +63,8 @@ Zotero.Translate.SandboxManager = function(sandboxLocation) {
 		
 		// expose parseFromString
 		this.__exposedProps__ = {"parseFromString":"r"};
-		if(Zotero.isFx5) {
-			this.parseFromString = function(str, contentType) {
-				return Zotero.Translate.SandboxManager.Fx5DOMWrapper(_DOMParser.parseFromString(str, contentType));
-			}
-		} else {
-			this.parseFromString = function(str, contentType) _DOMParser.parseFromString(str, contentType);
+		this.parseFromString = function(str, contentType) {
+			return Zotero.Translate.SandboxManager.Fx5DOMWrapper(_DOMParser.parseFromString(str, contentType));
 		}
 	};
 	this.sandbox.DOMParser.__exposedProps__ = {"prototype":"r"};
diff --git a/install.rdf b/install.rdf
index bfb30488fb..71bdaf0a72 100644
--- a/install.rdf
+++ b/install.rdf
@@ -25,8 +25,8 @@
     <em:targetApplication>
       <Description>
         <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
-        <em:minVersion>3.6</em:minVersion>
-        <em:maxVersion>15.0a1</em:maxVersion>
+        <em:minVersion>5.0</em:minVersion>
+        <em:maxVersion>19.0a1</em:maxVersion>
       </Description>
     </em:targetApplication>
     
diff --git a/update.rdf b/update.rdf
index dc394f8da2..b7f16c2497 100644
--- a/update.rdf
+++ b/update.rdf
@@ -11,8 +11,8 @@
           <targetApplication>
             <RDF:Description>
               <id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</id>
-              <minVersion>3.6</minVersion>
-              <maxVersion>15.0a1</maxVersion>
+              <minVersion>5.0</minVersion>
+              <maxVersion>19.0a1</maxVersion>
               <updateLink>http://download.zotero.org/extension/zotero.xpi</updateLink>
               <updateHash>sha1:</updateHash>
             </RDF:Description>