diff --git a/index.js b/index.js
index 1057f5ff17..efca586644 100644
--- a/index.js
+++ b/index.js
@@ -206,20 +206,20 @@ RedisClient.prototype.do_auth = function () {
                 debug("Warning: Redis server does not require a password, but a password was supplied.");
                 err = null;
                 res = "OK";
+            } else if (self.auth_callback) {
+                self.auth_callback(err);
+                self.auth_callback = null;
             } else {
-                return self.emit("error", new Error("Auth error: " + err.message));
+                self.emit("error", err);
+                return;
             }
         }
 
         res = res.toString();
-        if (res !== "OK") {
-            return self.emit("error", new Error("Auth failed: " + res));
-        }
-
         debug("Auth succeeded " + self.address + " id " + self.connection_id);
 
         if (self.auth_callback) {
-            self.auth_callback(err, res);
+            self.auth_callback(null, res);
             self.auth_callback = null;
         }
 
@@ -509,6 +509,7 @@ RedisClient.prototype.on_data = function (data) {
 
 RedisClient.prototype.return_error = function (err) {
     var command_obj = this.command_queue.shift(), queue_len = this.command_queue.length;
+    err.command_used = command_obj.command.toUpperCase();
 
     if (this.pub_sub_mode === false && queue_len === 0) {
         this.command_queue = new Queue();
diff --git a/test/auth.spec.js b/test/auth.spec.js
index 57c88f707d..3a1c8812ca 100644
--- a/test/auth.spec.js
+++ b/test/auth.spec.js
@@ -34,19 +34,32 @@ describe("client authentication", function () {
                 });
             });
 
-            it("raises error when auth is bad", function (done) {
+            it("emits error when auth is bad without callback", function (done) {
                 if (helper.redisProcess().spawnFailed()) this.skip();
 
                 client = redis.createClient.apply(redis.createClient, args);
 
-                client.once('error', function (error) {
-                    assert.ok(/ERR invalid password/.test(error));
+                client.once('error', function (err) {
+                    assert.strictEqual(err.command_used, 'AUTH');
+                    assert.ok(/ERR invalid password/.test(err.message));
                     return done();
                 });
 
                 client.auth(auth + 'bad');
             });
 
+            it("returns an error when auth is bad with a callback", function (done) {
+                if (helper.redisProcess().spawnFailed()) this.skip();
+
+                client = redis.createClient.apply(redis.createClient, args);
+
+                client.auth(auth + 'bad', function (err, res) {
+                    assert.strictEqual(err.command_used, 'AUTH');
+                    assert.ok(/ERR invalid password/.test(err.message));
+                    done();
+                });
+            });
+
             if (ip === 'IPv4') {
                 it('allows auth to be provided as part of redis url', function (done) {
                     if (helper.redisProcess().spawnFailed()) this.skip();
@@ -70,6 +83,19 @@ describe("client authentication", function () {
                 });
             });
 
+            it('allows auth and no_ready_check to be provided as config option for client', function (done) {
+                if (helper.redisProcess().spawnFailed()) this.skip();
+
+                var args = config.configureClient(parser, ip, {
+                    auth_pass: auth,
+                    no_ready_check: true
+                });
+                client = redis.createClient.apply(redis.createClient, args);
+                client.on("ready", function () {
+                    done();
+                });
+            });
+
             it('allows auth to be provided post-hoc with auth method', function (done) {
                 if (helper.redisProcess().spawnFailed()) this.skip();
 
diff --git a/test/commands/select.spec.js b/test/commands/select.spec.js
index cb3e101c2f..32e5b0a27e 100644
--- a/test/commands/select.spec.js
+++ b/test/commands/select.spec.js
@@ -94,6 +94,7 @@ describe("The 'select' method", function () {
                             assert.strictEqual(client.selected_db, null, "default db should be null");
 
                             client.on('error', function (err) {
+                                assert.strictEqual(err.command_used, 'SELECT');
                                 assert.equal(err.message, 'ERR invalid DB index');
                                 done();
                             });