diff --git a/.travis.yml b/.travis.yml
index 0c4ba7d..1233073 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: objective-c
-osx_image: xcode8.3.2
+osx_image: xcode8.3
 sudo: false
 git:
   submodules: false
diff --git a/CoreStoreTests/DynamicModelTests.swift b/CoreStoreTests/DynamicModelTests.swift
index 02fea11..b63c708 100644
--- a/CoreStoreTests/DynamicModelTests.swift
+++ b/CoreStoreTests/DynamicModelTests.swift
@@ -28,12 +28,18 @@ import XCTest
 @testable
 import CoreStore
 
+#if os(OSX)
+    typealias Color = NSColor
+#else
+    
+    typealias Color = UIColor
+#endif
 
 class Animal: CoreStoreObject {
     
     let species = Value.Required<String>("species", default: "Swift")
     let master = Relationship.ToOne<Person>("master")
-    let color = Transformable.Optional<UIColor>("color")
+    let color = Transformable.Optional<Color>("color")
 }
 
 class Dog: Animal {
@@ -102,7 +108,7 @@ class DynamicModelTests: BaseTestDataTestCase {
                     XCTAssertEqual(animal.species.value, "Sparrow")
                     
                     animal.color .= .yellow
-                    XCTAssertEqual(animal.color.value, UIColor.yellow)
+                    XCTAssertEqual(animal.color.value, Color.yellow)
                     
                     let dog = transaction.create(Into<Dog>())
                     XCTAssertEqual(dog.species.value, "Swift")
@@ -168,7 +174,6 @@ class DynamicModelTests: BaseTestDataTestCase {
                 success: {
             
                     fetchDone.fulfill()
-                    withExtendedLifetime(stack, {})
                 },
                 failure: { _ in
                     
diff --git a/Sources/CSUnsafeDataTransaction.swift b/Sources/CSUnsafeDataTransaction.swift
index e0f0ee7..002bae3 100644
--- a/Sources/CSUnsafeDataTransaction.swift
+++ b/Sources/CSUnsafeDataTransaction.swift
@@ -47,6 +47,10 @@ public final class CSUnsafeDataTransaction: CSBaseDataTransaction {
         
         self.bridgeToSwift.context.saveAsynchronouslyWithCompletion { (_, error) in
             
+            defer {
+                
+                withExtendedLifetime(self, {})
+            }
             if let error = error {
                 
                 failure?(error.bridgeToObjectiveC)
@@ -55,7 +59,6 @@ public final class CSUnsafeDataTransaction: CSBaseDataTransaction {
                 
                 success?()
             }
-            withExtendedLifetime(self, {})
         }
     }
     
@@ -217,6 +220,10 @@ public final class CSUnsafeDataTransaction: CSBaseDataTransaction {
         
         self.bridgeToSwift.context.saveAsynchronouslyWithCompletion { (hasChanges, error) in
             
+            defer {
+                
+                withExtendedLifetime(self, {})
+            }
             if let error = error {
                 
                 completion?(SaveResult(error).bridgeToObjectiveC)
@@ -225,7 +232,6 @@ public final class CSUnsafeDataTransaction: CSBaseDataTransaction {
                 
                 completion?(SaveResult(hasChanges: hasChanges).bridgeToObjectiveC)
             }
-            withExtendedLifetime(self, {})
         }
     }
     
diff --git a/Sources/DataStack+Transaction.swift b/Sources/DataStack+Transaction.swift
index 68c4b38..52a09c7 100644
--- a/Sources/DataStack+Transaction.swift
+++ b/Sources/DataStack+Transaction.swift
@@ -63,7 +63,7 @@ public extension DataStack {
             
             defer {
                 
-                withExtendedLifetime(transaction, {})
+                withExtendedLifetime((self, transaction), {})
             }
             let userInfo: T
             do {
@@ -112,7 +112,7 @@ public extension DataStack {
             
             defer {
                 
-                withExtendedLifetime(transaction, {})
+                withExtendedLifetime((self, transaction), {})
             }
             let userInfo: T
             do {