diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2ed209eb..804e22c5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+#### Version 2.3.1
+
+* Improved Swift 2.0 interoperability. (#178)
+
 #### Version 2.3.0
 
 * Raised deployment target to iOS 7.0 and OS X 10.9.
diff --git a/README.md b/README.md
index be989182..c486645d 100644
--- a/README.md
+++ b/README.md
@@ -30,12 +30,12 @@ XCDYouTubeKit is available through CocoaPods and Carthage.
 
 CocoaPods:
 ```ruby
-pod "XCDYouTubeKit", "~> 2.3.0"
+pod "XCDYouTubeKit", "~> 2.3.1"
 ```
 
 Carthage:
 ```objc
-github "0xced/XCDYouTubeKit" ~> 2.3.0
+github "0xced/XCDYouTubeKit" ~> 2.3.1
 ```
 
 Alternatively, you can manually use the provided static library on iOS or dynamic framework on OS X. In order to use the iOS static library, you must:
diff --git a/XCDYouTubeKit Demo/XCDYouTubeKit Demo.xcodeproj/project.pbxproj b/XCDYouTubeKit Demo/XCDYouTubeKit Demo.xcodeproj/project.pbxproj
index 099352b8..668bf023 100644
--- a/XCDYouTubeKit Demo/XCDYouTubeKit Demo.xcodeproj/project.pbxproj	
+++ b/XCDYouTubeKit Demo/XCDYouTubeKit Demo.xcodeproj/project.pbxproj	
@@ -541,7 +541,7 @@
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer";
 				COPY_PHASE_STRIP = NO;
-				CURRENT_PROJECT_VERSION = 2.3.0;
+				CURRENT_PROJECT_VERSION = 2.3.1;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_DYNAMIC_NO_PIC = NO;
 				GCC_OPTIMIZATION_LEVEL = 0;
@@ -576,7 +576,7 @@
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
 				"CODE_SIGN_IDENTITY[sdk=iphoneos*]" = "iPhone Developer";
 				COPY_PHASE_STRIP = YES;
-				CURRENT_PROJECT_VERSION = 2.3.0;
+				CURRENT_PROJECT_VERSION = 2.3.1;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
 				GCC_PREPROCESSOR_DEFINITIONS = (
 					"NS_BLOCK_ASSERTIONS=1",
diff --git a/XCDYouTubeKit.podspec b/XCDYouTubeKit.podspec
index cbbd71c8..0d5f4519 100644
--- a/XCDYouTubeKit.podspec
+++ b/XCDYouTubeKit.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name                  = "XCDYouTubeKit"
-  s.version               = "2.3.0"
+  s.version               = "2.3.1"
   s.summary               = "YouTube video player for iOS and OS X."
   s.homepage              = "https://github.com/0xced/XCDYouTubeKit"
   s.screenshot            = "https://raw.github.com/0xced/XCDYouTubeKit/#{s.version}/Screenshots/XCDYouTubeVideoPlayerViewController.png"
diff --git a/XCDYouTubeKit.xcodeproj/project.pbxproj b/XCDYouTubeKit.xcodeproj/project.pbxproj
index 82ed4d12..d69e1522 100644
--- a/XCDYouTubeKit.xcodeproj/project.pbxproj
+++ b/XCDYouTubeKit.xcodeproj/project.pbxproj
@@ -875,7 +875,7 @@
 				COPY_PHASE_STRIP = NO;
 				CURRENT_PROJECT_VERSION = "$(DYLIB_CURRENT_VERSION)";
 				DYLIB_COMPATIBILITY_VERSION = 2.0.0;
-				DYLIB_CURRENT_VERSION = 2.3.0;
+				DYLIB_CURRENT_VERSION = 2.3.1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
@@ -929,7 +929,7 @@
 				COPY_PHASE_STRIP = YES;
 				CURRENT_PROJECT_VERSION = "$(DYLIB_CURRENT_VERSION)";
 				DYLIB_COMPATIBILITY_VERSION = 2.0.0;
-				DYLIB_CURRENT_VERSION = 2.3.0;
+				DYLIB_CURRENT_VERSION = 2.3.1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
@@ -996,7 +996,7 @@
 				COPY_PHASE_STRIP = NO;
 				CURRENT_PROJECT_VERSION = "$(DYLIB_CURRENT_VERSION)";
 				DYLIB_COMPATIBILITY_VERSION = 2.0.0;
-				DYLIB_CURRENT_VERSION = 2.3.0;
+				DYLIB_CURRENT_VERSION = 2.3.1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				GCC_C_LANGUAGE_STANDARD = gnu99;
diff --git a/XCDYouTubeKit/XCDYouTubeClient.h b/XCDYouTubeKit/XCDYouTubeClient.h
index c9e7938c..00e67152 100644
--- a/XCDYouTubeKit/XCDYouTubeClient.h
+++ b/XCDYouTubeKit/XCDYouTubeClient.h
@@ -6,6 +6,7 @@
 #define NS_ASSUME_NONNULL_BEGIN
 #define NS_ASSUME_NONNULL_END
 #define nullable
+#define __nullable
 #endif
 
 #import <Foundation/Foundation.h>
@@ -76,7 +77,7 @@ NS_ASSUME_NONNULL_BEGIN
  *
  *  @return An opaque object conforming to the `<XCDYouTubeOperation>` protocol for canceling the asynchronous video information operation. If you call the `cancel` method before the operation is finished, the completion handler will not be called. It is recommended that you store this opaque object as a weak property.
  */
-- (id<XCDYouTubeOperation>) getVideoWithIdentifier:(nullable NSString *)videoIdentifier completionHandler:(void (^)(XCDYouTubeVideo *video, NSError *error))completionHandler;
+- (id<XCDYouTubeOperation>) getVideoWithIdentifier:(nullable NSString *)videoIdentifier completionHandler:(void (^)(XCDYouTubeVideo * __nullable video, NSError * __nullable error))completionHandler;
 
 @end
 
diff --git a/XCDYouTubeKit/XCDYouTubeClient.m b/XCDYouTubeKit/XCDYouTubeClient.m
index 6413b3ad..0adf8225 100644
--- a/XCDYouTubeKit/XCDYouTubeClient.m
+++ b/XCDYouTubeKit/XCDYouTubeClient.m
@@ -54,7 +54,7 @@ - (NSString *) languageIdentifier
 	return _languageIdentifier;
 }
 
-- (id<XCDYouTubeOperation>) getVideoWithIdentifier:(NSString *)videoIdentifier completionHandler:(void (^)(XCDYouTubeVideo *video, NSError *error))completionHandler
+- (id<XCDYouTubeOperation>) getVideoWithIdentifier:(NSString *)videoIdentifier completionHandler:(void (^)(XCDYouTubeVideo * __nullable video, NSError * __nullable error))completionHandler
 {
 	if (!completionHandler)
 		@throw [NSException exceptionWithName:NSInvalidArgumentException reason:@"The `completionHandler` argument must not be nil." userInfo:nil];