diff --git a/CardIO.podspec b/CardIO.podspec
index 504a414..dc076b0 100644
--- a/CardIO.podspec
+++ b/CardIO.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |spec|
   spec.name             = 'CardIO'
-  spec.version          = '5.3.0'
+  spec.version          = '5.3.1'
   spec.license          = { type: 'MIT', file: 'LICENSE.md' }
   spec.homepage         = 'https://www.card.io'
   spec.authors          = { 'CardIO' => 'support@paypal.com' }
diff --git a/CardIO/CardIO.h b/CardIO/CardIO.h
index 7eb3a3d..c05d79b 100644
--- a/CardIO/CardIO.h
+++ b/CardIO/CardIO.h
@@ -1,6 +1,6 @@
 //
 //  CardIO.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOCreditCardInfo.h b/CardIO/CardIOCreditCardInfo.h
index d6c5e3d..035c4dc 100644
--- a/CardIO/CardIOCreditCardInfo.h
+++ b/CardIO/CardIOCreditCardInfo.h
@@ -1,6 +1,6 @@
 //
 //  CardIOCreditCardInfo.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIODetectionMode.h b/CardIO/CardIODetectionMode.h
index 0b1dc89..3032df0 100644
--- a/CardIO/CardIODetectionMode.h
+++ b/CardIO/CardIODetectionMode.h
@@ -1,6 +1,6 @@
 //
 //  CardIODetectionMode.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOPaymentViewController.h b/CardIO/CardIOPaymentViewController.h
index fc08bfa..aa62ce1 100644
--- a/CardIO/CardIOPaymentViewController.h
+++ b/CardIO/CardIOPaymentViewController.h
@@ -1,6 +1,6 @@
 //
 //  CardIOPaymentViewController.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOPaymentViewControllerDelegate.h b/CardIO/CardIOPaymentViewControllerDelegate.h
index a78715a..99e9e78 100644
--- a/CardIO/CardIOPaymentViewControllerDelegate.h
+++ b/CardIO/CardIOPaymentViewControllerDelegate.h
@@ -1,6 +1,6 @@
 //
 //  CardIOPaymentViewControllerDelegate.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOUtilities.h b/CardIO/CardIOUtilities.h
index 9da00f8..95462ad 100644
--- a/CardIO/CardIOUtilities.h
+++ b/CardIO/CardIOUtilities.h
@@ -1,6 +1,6 @@
 //
 //  CardIOUtilities.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOView.h b/CardIO/CardIOView.h
index ec68b87..44bbd81 100644
--- a/CardIO/CardIOView.h
+++ b/CardIO/CardIOView.h
@@ -1,6 +1,6 @@
 //
 //  CardIOView.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/CardIOViewDelegate.h b/CardIO/CardIOViewDelegate.h
index be31dba..a2cdd24 100644
--- a/CardIO/CardIOViewDelegate.h
+++ b/CardIO/CardIOViewDelegate.h
@@ -1,6 +1,6 @@
 //
 //  CardIOViewDelegate.h
-//  Version 5.3.0
+//  Version 5.3.1
 //
 //  See the file "LICENSE.md" for the full license governing this code.
 //
diff --git a/CardIO/libCardIO.a b/CardIO/libCardIO.a
index 1022d32..4eefea3 100644
Binary files a/CardIO/libCardIO.a and b/CardIO/libCardIO.a differ
diff --git a/release_notes.txt b/release_notes.txt
index 7352130..49dd0db 100644
--- a/release_notes.txt
+++ b/release_notes.txt
@@ -1,6 +1,12 @@
 card.io iOS SDK release notes
 =============================
 
+5.3.1 (Tue 01/26/2016)
+
+* Prevent an issue with crashes when an invalid IplImage is used for
+  scanning causing an exception to be thrown later in cvGetSize().
+  ( https://github.com/card-io/card.io-iOS-source/pull/57 )
+
 5.3.0 (Mon 12/21/2015)
 
 * Add cardholder name for manual text input. Thanks to Mark Rogers and