diff --git a/ABPadLockScreen/ABPadLockScreenAbstractViewController.m b/ABPadLockScreen/ABPadLockScreenAbstractViewController.m
index 664e407..d720870 100755
--- a/ABPadLockScreen/ABPadLockScreenAbstractViewController.m
+++ b/ABPadLockScreen/ABPadLockScreenAbstractViewController.m
@@ -108,7 +108,7 @@ - (UIStatusBarStyle)preferredStatusBarStyle
 	
 	if(color == nil)
 	{
-		color = lockScreenView.backgroundColor = [UIColor blackColor];
+		color = [UIColor blackColor];
 	}
 	
 	const CGFloat *componentColors = CGColorGetComponents(color.CGColor);
diff --git a/ABPadLockScreen/ABPadLockScreenSetupViewController.h b/ABPadLockScreen/ABPadLockScreenSetupViewController.h
index 409375b..375a129 100755
--- a/ABPadLockScreen/ABPadLockScreenSetupViewController.h
+++ b/ABPadLockScreen/ABPadLockScreenSetupViewController.h
@@ -37,6 +37,7 @@
 @property (nonatomic, strong, readonly) NSString *subtitleLabelText;
 @property (nonatomic, strong) NSString *pinNotMatchedText;
 @property (nonatomic, strong) NSString *pinConfirmationText;
+@property (nonatomic, strong) NSString *invalidPinText;
 
 - (instancetype)initWithDelegate:(id<ABPadLockScreenSetupViewControllerDelegate>)delegate;
 - (instancetype)initWithDelegate:(id<ABPadLockScreenSetupViewControllerDelegate>)delegate complexPin:(BOOL)complexPin;
@@ -48,5 +49,7 @@
 @required
 - (void)pinSet:(NSString *)pin padLockScreenSetupViewController:(ABPadLockScreenSetupViewController *)padLockScreenViewController;
 - (void)unlockWasCancelledForSetupViewController:(ABPadLockScreenAbstractViewController *)padLockScreenViewController;
+@optional
+- (BOOL)isValidPin:(NSString *)pin padLockScreenSetupViewController:(ABPadLockScreenSetupViewController *)padLockScreenViewController;
 
 @end
\ No newline at end of file
diff --git a/ABPadLockScreen/ABPadLockScreenSetupViewController.m b/ABPadLockScreen/ABPadLockScreenSetupViewController.m
index 24221c7..92a775a 100755
--- a/ABPadLockScreen/ABPadLockScreenSetupViewController.m
+++ b/ABPadLockScreen/ABPadLockScreenSetupViewController.m
@@ -75,6 +75,7 @@ - (void)setDefaultTexts
 {
     _pinNotMatchedText = NSLocalizedString(@"Pincode did not match.", @"");
     _pinConfirmationText = NSLocalizedString(@"Re-enter your new pincode", @"");
+    _invalidPinText = NSLocalizedString(@"Invalid pincode", @"");
 }
 
 #pragma mark -
@@ -91,7 +92,7 @@ - (void)processPin
 {
     if (!self.enteredPin)
     {
-        [self startPinConfirmation];
+        [self validatePin];
     }
     else
     {
@@ -99,6 +100,12 @@ - (void)processPin
     }
 }
 
+- (void)invalidateCurrentPin
+{
+    self.enteredPin = nil;
+    self.currentPin = @"";
+}
+
 - (void)startPinConfirmation
 {
     self.enteredPin = self.currentPin;
@@ -106,7 +113,24 @@ - (void)startPinConfirmation
     [lockScreenView updateDetailLabelWithString:self.pinConfirmationText animated:YES completion:nil];
     [lockScreenView resetAnimated:YES];
 }
-         
+
+- (void)validatePin
+{
+    BOOL isValidPin = YES;
+    if ([self.setupScreenDelegate respondsToSelector:@selector(isValidPin:padLockScreenSetupViewController:)])
+    {
+        isValidPin = [self.setupScreenDelegate isValidPin:self.currentPin padLockScreenSetupViewController:self];
+    }
+    if (isValidPin)
+    {
+        [self startPinConfirmation];
+    }
+    else
+    {
+        [self resetPinWithErrorString:self.invalidPinText];
+    }
+}
+
 - (void)validateConfirmedPin
 {
     if ([self.currentPin isEqualToString:self.enteredPin])
@@ -118,17 +142,21 @@ - (void)validateConfirmedPin
     }
     else
     {
-        [lockScreenView updateDetailLabelWithString:self.pinNotMatchedText animated:YES completion:nil];
-		[lockScreenView animateFailureNotification];
-        [lockScreenView resetAnimated:YES];
-        self.enteredPin = nil;
-        self.currentPin = @"";
-        
-        // viberate feedback
-        if (self.errorVibrateEnabled)
-        {
-            AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
-        }
+        [self resetPinWithErrorString:self.pinNotMatchedText];
+    }
+}
+
+- (void)resetPinWithErrorString:(NSString *)errorString {
+    [lockScreenView updateDetailLabelWithString:errorString animated:YES completion:nil];
+    [lockScreenView animateFailureNotification];
+    [lockScreenView resetAnimated:YES];
+    self.enteredPin = nil;
+    self.currentPin = @"";
+
+    // viberate feedback
+    if (self.errorVibrateEnabled)
+    {
+        AudioServicesPlaySystemSound(kSystemSoundID_Vibrate);
     }
 }
 
diff --git a/ABPadLockScreen/ABPadLockScreenViewController.m b/ABPadLockScreen/ABPadLockScreenViewController.m
index a9b7418..6cabbb6 100755
--- a/ABPadLockScreen/ABPadLockScreenViewController.m
+++ b/ABPadLockScreen/ABPadLockScreenViewController.m
@@ -123,13 +123,17 @@ - (void)processFailure
     
     if (self.remainingAttempts > 1)
     {
-        [lockScreenView updateDetailLabelWithString:[NSString stringWithFormat:@"%ld %@", (long)self.remainingAttempts, self.pluralAttemptsLeftString]
-                                           animated:YES completion:nil];
+        if (self.pluralAttemptsLeftString) {
+            [lockScreenView updateDetailLabelWithString:[NSString stringWithFormat:@"%ld %@", (long)self.remainingAttempts, self.pluralAttemptsLeftString]
+                                               animated:YES completion:nil];
+        }
     }
     else if (self.remainingAttempts == 1)
     {
-        [lockScreenView updateDetailLabelWithString:[NSString stringWithFormat:@"%ld %@", (long)self.remainingAttempts, self.singleAttemptLeftString]
-                                           animated:YES completion:nil];
+        if (self.singleAttemptLeftString) {
+            [lockScreenView updateDetailLabelWithString:[NSString stringWithFormat:@"%ld %@", (long)self.remainingAttempts, self.singleAttemptLeftString]
+                                               animated:YES completion:nil];
+        }
     }
     else if (self.remainingAttempts == 0)
     {
diff --git a/ABPadLockScreenDemo/ABPadLockScreenDemo/Your Modules/ExampleViewController.m b/ABPadLockScreenDemo/ABPadLockScreenDemo/Your Modules/ExampleViewController.m
index 0c5a3fa..1ca7952 100644
--- a/ABPadLockScreenDemo/ABPadLockScreenDemo/Your Modules/ExampleViewController.m	
+++ b/ABPadLockScreenDemo/ABPadLockScreenDemo/Your Modules/ExampleViewController.m	
@@ -48,6 +48,7 @@ - (IBAction)setPin:(id)sender
     ABPadLockScreenSetupViewController *lockScreen = [[ABPadLockScreenSetupViewController alloc] initWithDelegate:self complexPin:YES subtitleLabelText:@"You need a PIN to continue"];
     lockScreen.tapSoundEnabled = YES;
     lockScreen.errorVibrateEnabled = YES;
+    lockScreen.invalidPinText = @"Invalid pin";
 	
     lockScreen.modalPresentationStyle = UIModalPresentationFullScreen;
     lockScreen.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;
@@ -126,4 +127,8 @@ - (void)unlockWasCancelledForSetupViewController:(ABPadLockScreenAbstractViewCon
     NSLog(@"Pin Setup Cnaclled");
 }
 
+- (BOOL)isValidPin:(NSString *)pin padLockScreenSetupViewController:(ABPadLockScreenSetupViewController *)padLockScreenViewController {
+    return ![pin isEqualToString:@"0000"];
+}
+
 @end
diff --git a/ABPadLockScreenSwiftDemo/ABPadLockScreenSwiftDemo/ViewController.swift b/ABPadLockScreenSwiftDemo/ABPadLockScreenSwiftDemo/ViewController.swift
index 0e278b9..591cd12 100644
--- a/ABPadLockScreenSwiftDemo/ABPadLockScreenSwiftDemo/ViewController.swift
+++ b/ABPadLockScreenSwiftDemo/ABPadLockScreenSwiftDemo/ViewController.swift
@@ -50,6 +50,7 @@ class ViewController: UIViewController, ABPadLockScreenSetupViewControllerDelega
     
     @IBAction func setPinSelected(sender: AnyObject) {
         let lockSetupScreen = ABPadLockScreenSetupViewController(delegate: self, complexPin: false, subtitleLabelText: "Select a pin")
+        lockSetupScreen.invalidPinText = "Invalid pin"
         lockSetupScreen.tapSoundEnabled = true
         lockSetupScreen.errorVibrateEnabled = true
         lockSetupScreen.modalPresentationStyle = UIModalPresentationStyle.FullScreen
@@ -67,6 +68,10 @@ class ViewController: UIViewController, ABPadLockScreenSetupViewControllerDelega
     func unlockWasCancelledForSetupViewController(padLockScreenViewController: ABPadLockScreenAbstractViewController!) {
         dismissViewControllerAnimated(true, completion: nil)
     }
+
+    func isValidPin(pin: String!, padLockScreenSetupViewController padLockScreenViewController: ABPadLockScreenSetupViewController!) -> Bool {
+        return pin != "0000"
+    }
     
     //MARK: Lock Screen Delegate
     func padLockScreenViewController(padLockScreenViewController: ABPadLockScreenViewController!, validatePin pin: String!) -> Bool {