diff --git a/AZTransitions.podspec b/AZTransitions.podspec
index bced3b3..0cec8d9 100644
--- a/AZTransitions.podspec
+++ b/AZTransitions.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "AZTransitions"
-  s.version      = "0.21"
+  s.version      = "0.22"
   s.summary      = "Framework that helps you to work with custom modal transtions."
   s.description  = <<-DESC
                     With this framework can easily work with custom modal transitions. CustomModalTransition class provides you with all nesessary API, so you should only think about aniamtions.
diff --git a/Source/CustomModalTransition.swift b/Source/CustomModalTransition.swift
index a39c91a..e0c47af 100644
--- a/Source/CustomModalTransition.swift
+++ b/Source/CustomModalTransition.swift
@@ -53,8 +53,8 @@ open class CustomModalTransition: NSObject {
   
   // MARK: - Transition Parameters
   
-  public fileprivate(set) var transitionContext: UIViewControllerContextTransitioning!
-  public fileprivate(set) var transitionContainerView: UIView!
+  public fileprivate(set) weak var transitionContext: UIViewControllerContextTransitioning!
+  public fileprivate(set) weak var transitionContainerView: UIView!
   public fileprivate(set) var isPresenting: Bool = false
   public fileprivate(set) var isInteractive: Bool = false
   
@@ -62,12 +62,12 @@ open class CustomModalTransition: NSObject {
   // You can choose any pair
   
   // Presented/preseting style view controllees
-  public fileprivate(set) var presentedViewController: UIViewController!
-  public fileprivate(set) var presentingViewController: UIViewController!
+  public fileprivate(set) weak var presentedViewController: UIViewController!
+  public fileprivate(set) weak var presentingViewController: UIViewController!
   
   // Apple style view controllers
-  public fileprivate(set) var fromViewController: UIViewController!
-  public fileprivate(set) var toViewController: UIViewController!
+  public fileprivate(set) weak var fromViewController: UIViewController!
+  public fileprivate(set) weak var toViewController: UIViewController!
   
   public func viewControllerFor(type: TransitionViewControllerType) -> UIViewController {
     switch type {
@@ -120,6 +120,7 @@ open class CustomModalTransition: NSObject {
   }
   
   public func cancelInteractiveTransition() {
+    // http://openradar.appspot.com/14675246
     interactionController.completionSpeed = 0.999 // http://stackoverflow.com/a/22968139/188461
     interactionController.cancel()
     
@@ -183,7 +184,7 @@ open class CustomModalTransition: NSObject {
   // MARK: - Private
   
   fileprivate var interactionController: UIPercentDrivenInteractiveTransition!
-  fileprivate var owningController: UIViewController!
+  fileprivate weak var owningController: UIViewController!
 }
 
 // MARK: - UIViewControllerTransitioningDelegate
diff --git a/Source/Info.plist b/Source/Info.plist
index 1c17c9e..c9d8ad7 100644
--- a/Source/Info.plist
+++ b/Source/Info.plist
@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>0.21</string>
+	<string>0.22</string>
 	<key>CFBundleVersion</key>
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>NSPrincipalClass</key>