diff --git a/chrome/content/zotero/xpcom/schema.js b/chrome/content/zotero/xpcom/schema.js
index be1746cc9..31669e5ad 100644
--- a/chrome/content/zotero/xpcom/schema.js
+++ b/chrome/content/zotero/xpcom/schema.js
@@ -663,6 +663,7 @@ Zotero.Schema = new function(){
 		//
 		var sql = "SELECT version FROM version WHERE schema=?";
 		var lastModTime = yield Zotero.DB.valueQueryAsync(sql, mode);
+		var cache = {};
 		
 		// XPI installation
 		if (!isUnpacked) {
@@ -880,6 +881,9 @@ Zotero.Schema = new function(){
 						else if (mode == 'translators') {
 							newObj = yield Zotero.Translators.loadFromFile(entry.path);
 						}
+						else {
+							throw new Error("Invalid mode '" + mode + "'");
+						}
 						let existingObj = Zotero[Mode].get(newObj[modeType + "ID"]);
 						if (!existingObj) {
 							Zotero.debug("Installing " + modeType + " '" + newObj[titleField] + "'");
@@ -902,19 +906,16 @@ Zotero.Schema = new function(){
 						}
 						
 						try {
-							let destFile = OS.Path.join(destDir, fileName);
+							let destFile;
+							if (!existingObj || !existingObj.hidden) {
+								destFile = OS.Path.join(destDir, fileName);
+							}
+							else {
+								destFile = OS.Path.join(hiddenDir, fileName)
+							}
 							
 							try {
-								if (!existingObj || !existingObj.hidden) {
-									yield OS.File.copy(entry.path, destFile, {
-										noOverwrite: true
-									});
-								}
-								else {
-									yield OS.File.copy(entry.path, OS.Path.join(hiddenDir, fileName), {
-										noOverwrite: true
-									});
-								}
+								yield OS.File.copy(entry.path, destFile, { noOverwrite: true });
 							}
 							catch (e) {
 								if (e instanceof OS.File.Error && e.becauseExists) {
@@ -923,17 +924,16 @@ Zotero.Schema = new function(){
 										+ "'" + fileName + "'";
 									Zotero.debug(msg, 1);
 									Components.utils.reportError(msg);
-									if (!existingObj || !existingObj.hidden) {
-										yield OS.File.copy(entry.path, destFile);
-									}
-									else {
-										yield OS.File.copy(entry.path, OS.Path.join(hiddenDir, fileName));
-									}
+									yield OS.File.copy(entry.path, destFile);
 								}
 								else {
 									throw e;
 								}
 							}
+							
+							if (mode == 'translators') {
+								cache[fileName] = newObj.metadata;
+							}
 						}
 						catch (e) {
 							Components.utils.reportError("Error copying file " + fileName + ": " + e);
@@ -956,7 +956,7 @@ Zotero.Schema = new function(){
 			}
 		});
 		
-		yield Zotero[Mode].reinit();
+		yield Zotero[Mode].reinit(cache);
 		
 		return true;
 	});
diff --git a/chrome/content/zotero/xpcom/translation/translator.js b/chrome/content/zotero/xpcom/translation/translator.js
index 88ba12d3b..ab98c32d9 100644
--- a/chrome/content/zotero/xpcom/translation/translator.js
+++ b/chrome/content/zotero/xpcom/translation/translator.js
@@ -59,6 +59,7 @@ var TRANSLATOR_SAVE_PROPERTIES = TRANSLATOR_REQUIRED_PROPERTIES.concat(["browser
  * @property {Object} hiddenPrefs Hidden preferences configurable through about:config
  * @property {Boolean} inRepository Whether the translator may be found in the repository
  * @property {String} lastUpdated SQL-style date and time of translator's last update
+ * @property {Object} metadata - Metadata block as object
  * @property {String} code The executable JavaScript for the translator
  * @property {Boolean} cacheCode Whether to cache code for this session (non-connector only)
  * @property {String} [path] File path corresponding to this translator (non-connector only)
@@ -129,6 +130,11 @@ Zotero.Translator.prototype.init = function(info) {
 	} else if(this.hasOwnProperty("code")) {
 		delete this.code;
 	}
+	// Save a copy of the metadata block
+	delete info.path;
+	delete info.code;
+	this.metadata = info;
+
 }
 
 /**
@@ -192,6 +198,7 @@ Zotero.Translator.prototype.logError = function(message, type, line, lineNumber,
 		var ios = Components.classes["@mozilla.org/network/io-service;1"].
 			getService(Components.interfaces.nsIIOService);
 		Zotero.log(message, type ? type : "error", ios.newFileURI(file).spec);
+		Zotero.debug(message, 1);
 	} else {
 		Zotero.logError(message);
 	}
diff --git a/chrome/content/zotero/xpcom/translation/translators.js b/chrome/content/zotero/xpcom/translation/translators.js
index 91c2cd046..e32ef58e3 100644
--- a/chrome/content/zotero/xpcom/translation/translators.js
+++ b/chrome/content/zotero/xpcom/translation/translators.js
@@ -23,6 +23,8 @@
     ***** END LICENSE BLOCK *****
 */
 
+"use strict";
+
 // Enumeration of types of translators
 const TRANSLATOR_TYPES = {"import":1, "export":2, "web":4, "search":8};
 
@@ -36,8 +38,11 @@ Zotero.Translators = new function() {
 	
 	/**
 	 * Initializes translator cache, loading all translator metadata into memory
+	 *
+	 * @param {Object} [memCache] - Translator metadata keyed by filename, if already available
+	 *                              (e.g., in updateBundledFiles()), to avoid unnecesary file reads
 	 */
-	this.reinit = Zotero.Promise.coroutine(function* () {
+	this.reinit = Zotero.Promise.coroutine(function* (memCache) {
 		Zotero.debug("Initializing translators");
 		var start = new Date;
 		_initialized = true;
@@ -76,7 +81,14 @@ Zotero.Translators = new function() {
 						lastModifiedTime = (yield OS.File.stat(path)).lastModificationDate.getTime();
 					}
 					
-					var dbCacheEntry = false;
+					// Check passed cache for metadata
+					let memCacheJSON = false;
+					if (memCache && memCache[fileName]) {
+						memCacheJSON = memCache[fileName];
+					}
+					
+					// Check DB cache
+					let dbCacheEntry = false;
 					if (dbCache[fileName]) {
 						filesInCache[fileName] = true;
 						if (dbCache[fileName].lastModifiedTime == lastModifiedTime) {
@@ -85,8 +97,10 @@ Zotero.Translators = new function() {
 					}
 					
 					// Get JSON from cache if possible
-					if(dbCacheEntry) {
-						var translator = Zotero.Translators.load(dbCacheEntry.metadataJSON, path);
+					if (memCacheJSON || dbCacheEntry) {
+						var translator = Zotero.Translators.load(
+							memCacheJSON || dbCacheEntry.metadataJSON, path
+						);
 					}
 					// Otherwise, load from file
 					else {
@@ -175,9 +189,13 @@ Zotero.Translators = new function() {
 
 	/**
 	 * Loads a translator from JSON, with optional code
+	 *
+	 * @param {String|Object} json - Metadata JSON
+	 * @param {String} path
+	 * @param {String} [code]
 	 */
 	this.load = function (json, path, code) {
-		var info = JSON.parse(json);
+		var info = typeof json == 'string' ? JSON.parse(json) : json;
 		info.path = path;
 		info.code = code;
 		return new Zotero.Translator(info);