diff --git a/chrome/content/zotero/xpcom/dataDirectory.js b/chrome/content/zotero/xpcom/dataDirectory.js
index 5bca15411f..2724db9d3c 100644
--- a/chrome/content/zotero/xpcom/dataDirectory.js
+++ b/chrome/content/zotero/xpcom/dataDirectory.js
@@ -180,10 +180,15 @@ Zotero.DataDirectory = {
 		// New installation of 5.0+ with no data directory specified, so check all the places the data
 		// could be
 		else {
-			Zotero.fxProfileAccessError = false;
+			let useProfile = false;
+			let useFirefoxProfile = false;
+			let useFirefoxProfileCustom = false;
+			let dataDirNamedAfterProfile = false;
 			
 			dataDir = this.defaultDir;
 			
+			Zotero.fxProfileAccessError = false;
+			
 			// If there's already a profile pointing to the default location, use a different
 			// data directory named after the profile, as long as one either doesn't exist yet or
 			// one does and it contains a database
@@ -194,6 +199,7 @@ Zotero.DataDirectory = {
 					if (!(yield OS.File.exists(newDataDir))
 							|| (yield OS.File.exists(OS.Path.join(newDataDir, dbFilename)))) {
 						dataDir = newDataDir;
+						dataDirNamedAfterProfile = true;
 					}
 				}
 			}
@@ -213,10 +219,6 @@ Zotero.DataDirectory = {
 				return dataDir;
 			}
 			
-			let useProfile = false;
-			let useFirefoxProfile = false;
-			let useFirefoxProfileCustom = false;
-			
 			// Check for <profile dir>/zotero/zotero.sqlite
 			let profileSubdirModTime;
 			try {
@@ -236,109 +238,111 @@ Zotero.DataDirectory = {
 			//
 			// Check Firefox directory
 			//
-			let profilesParent = OS.Path.dirname(Zotero.Profile.getOtherAppProfilesDir());
-			Zotero.debug("Looking for Firefox profile in " + profilesParent);
-			
-			// get default profile
-			var defProfile;
-			try {
-				defProfile = yield Zotero.Profile.getDefaultInProfilesDir(profilesParent);
-			}
-			catch (e) {
-				Zotero.debug("An error occurred locating the Firefox profile; "
-					+ "not attempting to migrate from Zotero for Firefox");
-				Zotero.logError(e);
-				Zotero.fxProfileAccessError = true;
-			}
-			if (defProfile) {
-				let profileDir = defProfile[0];
-				Zotero.debug("Found default profile at " + profileDir);
+			if (!dataDirNamedAfterProfile) {
+				let profilesParent = OS.Path.dirname(Zotero.Profile.getOtherAppProfilesDir());
+				Zotero.debug("Looking for Firefox profile in " + profilesParent);
 				
-				// Read in prefs
-				let prefsFile = OS.Path.join(profileDir, "prefs.js");
-				if (yield OS.File.exists(prefsFile)) {
-					let prefs = yield Zotero.Profile.readPrefsFromFile(prefsFile);
+				// get default profile
+				let defProfile;
+				try {
+					defProfile = yield Zotero.Profile.getDefaultInProfilesDir(profilesParent);
+				}
+				catch (e) {
+					Zotero.debug("An error occurred locating the Firefox profile; "
+						+ "not attempting to migrate from Zotero for Firefox");
+					Zotero.logError(e);
+					Zotero.fxProfileAccessError = true;
+				}
+				if (defProfile) {
+					let profileDir = defProfile[0];
+					Zotero.debug("Found default profile at " + profileDir);
 					
-					// Check for data dir pref
-					if (prefs['extensions.zotero.dataDir'] && prefs['extensions.zotero.useDataDir']) {
-						Zotero.debug(`Found custom dataDir of ${prefs['extensions.zotero.dataDir']}`);
-						let nsIFile;
-						try {
-							nsIFile = Components.classes["@mozilla.org/file/local;1"]
-								.createInstance(Components.interfaces.nsIFile);
-							nsIFile.persistentDescriptor = prefs['extensions.zotero.dataDir'];
-						}
-						catch (e) {
-							Zotero.logError(e);
-							if (!useProfile) {
-								Zotero.debug("Persistent descriptor in extensions.zotero.dataDir "
-									+ "did not resolve", 1);
-								throw { name: "NS_ERROR_FILE_NOT_FOUND" };
+					// Read in prefs
+					let prefsFile = OS.Path.join(profileDir, "prefs.js");
+					if (yield OS.File.exists(prefsFile)) {
+						let prefs = yield Zotero.Profile.readPrefsFromFile(prefsFile);
+						
+						// Check for data dir pref
+						if (prefs['extensions.zotero.dataDir'] && prefs['extensions.zotero.useDataDir']) {
+							Zotero.debug(`Found custom dataDir of ${prefs['extensions.zotero.dataDir']}`);
+							let nsIFile;
+							try {
+								nsIFile = Components.classes["@mozilla.org/file/local;1"]
+									.createInstance(Components.interfaces.nsIFile);
+								nsIFile.persistentDescriptor = prefs['extensions.zotero.dataDir'];
 							}
-						}
-						try {
-							let dbFile = OS.Path.join(nsIFile.path, dbFilename);
-							let mtime = (yield OS.File.stat(dbFile)).lastModificationDate;
-							Zotero.debug(`Database found at ${dbFile}, last modified ${mtime}`);
-							// If custom location has a newer DB, use that
-							if (!useProfile || mtime > profileSubdirModTime) {
-								dataDir = nsIFile.path;
-								useFirefoxProfileCustom = true;
-								useProfile = false;
-							}
-						}
-						catch (e) {
-							Zotero.logError(e);
-							// If we have a DB in the Zotero profile and get an error trying to
-							// access the custom location in Firefox, use the Zotero profile, since
-							// there's at least some chance it's right. Otherwise, throw an error.
-							if (!useProfile) {
-								// The error message normally gets the path from the pref, but
-								// we got it from the prefs file, so include it here
-								e.dataDir = nsIFile.path;
-								throw e;
-							}
-							Zotero.fxProfileAccessError = true;
-						}
-					}
-					// If no custom dir specified, check for a subdirectory
-					else {
-						try {
-							let dir = OS.Path.join(profileDir, this.legacyDirName);
-							let dbFile = OS.Path.join(dir, dbFilename);
-							let mtime = (yield OS.File.stat(dbFile)).lastModificationDate;
-							Zotero.debug(`Database found at ${dbFile}, last modified ${mtime}`);
-							// If newer than Zotero profile directory, use this one
-							if (!useProfile || mtime > profileSubdirModTime) {
-								dataDir = dir;
-								useFirefoxProfile = true;
-								useProfile = false;
-							}
-						}
-						// Legacy subdirectory doesn't exist or there was a problem accessing it, so
-						// just fall through to default location
-						catch (e) {
-							if (!(e instanceof OS.File.Error && e.becauseNoSuchFile)) {
+							catch (e) {
 								Zotero.logError(e);
+								if (!useProfile) {
+									Zotero.debug("Persistent descriptor in extensions.zotero.dataDir "
+										+ "did not resolve", 1);
+									throw { name: "NS_ERROR_FILE_NOT_FOUND" };
+								}
+							}
+							try {
+								let dbFile = OS.Path.join(nsIFile.path, dbFilename);
+								let mtime = (yield OS.File.stat(dbFile)).lastModificationDate;
+								Zotero.debug(`Database found at ${dbFile}, last modified ${mtime}`);
+								// If custom location has a newer DB, use that
+								if (!useProfile || mtime > profileSubdirModTime) {
+									dataDir = nsIFile.path;
+									useFirefoxProfileCustom = true;
+									useProfile = false;
+								}
+							}
+							catch (e) {
+								Zotero.logError(e);
+								// If we have a DB in the Zotero profile and get an error trying to
+								// access the custom location in Firefox, use the Zotero profile, since
+								// there's at least some chance it's right. Otherwise, throw an error.
+								if (!useProfile) {
+									// The error message normally gets the path from the pref, but
+									// we got it from the prefs file, so include it here
+									e.dataDir = nsIFile.path;
+									throw e;
+								}
 								Zotero.fxProfileAccessError = true;
 							}
 						}
-					}
-					
-					// If using data directory from Zotero for Firefox, transfer those prefs, because
-					// the fact that that DB was more recent and wasn't set in the Zotero profile prefs
-					// means that they were using Firefox.
-					if (useFirefoxProfile || useFirefoxProfileCustom) {
-						for (let key in prefs) {
-							if (key.substr(0, ZOTERO_CONFIG.PREF_BRANCH.length) === ZOTERO_CONFIG.PREF_BRANCH
-									&& key !== "extensions.zotero.firstRun2") {
-								Zotero.Prefs.set(key.substr(ZOTERO_CONFIG.PREF_BRANCH.length), prefs[key]);
+						// If no custom dir specified, check for a subdirectory
+						else {
+							try {
+								let dir = OS.Path.join(profileDir, this.legacyDirName);
+								let dbFile = OS.Path.join(dir, dbFilename);
+								let mtime = (yield OS.File.stat(dbFile)).lastModificationDate;
+								Zotero.debug(`Database found at ${dbFile}, last modified ${mtime}`);
+								// If newer than Zotero profile directory, use this one
+								if (!useProfile || mtime > profileSubdirModTime) {
+									dataDir = dir;
+									useFirefoxProfile = true;
+									useProfile = false;
+								}
+							}
+							// Legacy subdirectory doesn't exist or there was a problem accessing it, so
+							// just fall through to default location
+							catch (e) {
+								if (!(e instanceof OS.File.Error && e.becauseNoSuchFile)) {
+									Zotero.logError(e);
+									Zotero.fxProfileAccessError = true;
+								}
 							}
 						}
 						
-						// If data directory setting was transferred, use that
-						if (Zotero.Prefs.get('useDataDir')) {
-							return this.init();
+						// If using data directory from Zotero for Firefox, transfer those prefs, because
+						// the fact that that DB was more recent and wasn't set in the Zotero profile prefs
+						// means that they were using Firefox.
+						if (useFirefoxProfile || useFirefoxProfileCustom) {
+							for (let key in prefs) {
+								if (key.substr(0, ZOTERO_CONFIG.PREF_BRANCH.length) === ZOTERO_CONFIG.PREF_BRANCH
+										&& key !== "extensions.zotero.firstRun2") {
+									Zotero.Prefs.set(key.substr(ZOTERO_CONFIG.PREF_BRANCH.length), prefs[key]);
+								}
+							}
+							
+							// If data directory setting was transferred, use that
+							if (Zotero.Prefs.get('useDataDir')) {
+								return this.init();
+							}
 						}
 					}
 				}