diff --git a/src/providers/indexeddb.js b/src/providers/indexeddb.js
index 2658163..4975d60 100644
--- a/src/providers/indexeddb.js
+++ b/src/providers/indexeddb.js
@@ -9,6 +9,7 @@ define(function(require) {
 
   var IDB_RW = require('src/constants').IDB_RW;
   var IDB_RO = require('src/constants').IDB_RO;
+  var Errors = require('src/errors');
 
   function IndexedDBContext(db, mode) {
     var transaction = db.transaction(FILE_STORE_NAME, mode);
@@ -112,7 +113,7 @@ define(function(require) {
       callback(null, firstAccess);
     };
     openRequest.onerror = function onerror(error) {
-      callback(error);
+      callback(new Errors.EINVAL('IndexedDB cannot be accessed. If private browsing is enabled, disable it.'));
     };
   };
   IndexedDB.prototype.getReadOnlyContext = function() {
diff --git a/src/providers/websql.js b/src/providers/websql.js
index 4101de1..1b84deb 100644
--- a/src/providers/websql.js
+++ b/src/providers/websql.js
@@ -5,6 +5,7 @@ define(function(require) {
   var WSQL_SIZE = require('src/constants').WSQL_SIZE;
   var WSQL_DESC = require('src/constants').WSQL_DESC;
   var u8toArray = require('src/shared').u8toArray;
+  var Errors = require('src/errors');
 
   function WebSQLContext(db, isReadOnly) {
     var that = this;
@@ -116,6 +117,9 @@ define(function(require) {
     }
 
     function onError(transaction, error) {
+      if (error.code === 5) {
+        callback(new Errors.EINVAL('WebSQL access not authorized. If private browsing is enabled, disable it.'));
+      }
       callback(error);
     }
     function onSuccess(transaction, result) {