diff --git a/Examples/UIExplorer/LayoutEventsExample.js b/Examples/UIExplorer/LayoutEventsExample.js
index 6aec6257e..c57c4e5f2 100644
--- a/Examples/UIExplorer/LayoutEventsExample.js
+++ b/Examples/UIExplorer/LayoutEventsExample.js
@@ -49,8 +49,7 @@ var LayoutEventExample = React.createClass({
       () => {
         console.log('layout animation done.');
         this.addWrapText();
-      },
-      (error) => { throw new Error(JSON.stringify(error)); }
+      }
     );
     this.setState({
       viewStyle: {
diff --git a/Examples/UIExplorer/UIExplorerIntegrationTests/IntegrationTests.m b/Examples/UIExplorer/UIExplorerIntegrationTests/IntegrationTests.m
index 78e6c8265..85f73a314 100644
--- a/Examples/UIExplorer/UIExplorerIntegrationTests/IntegrationTests.m
+++ b/Examples/UIExplorer/UIExplorerIntegrationTests/IntegrationTests.m
@@ -26,11 +26,11 @@
 - (void)setUp
 {
 #if __LP64__
-  RCTAssert(false, @"Tests should be run on 32-bit device simulators (e.g. iPhone 5)");
+  RCTAssert(NO, @"Tests should be run on 32-bit device simulators (e.g. iPhone 5)");
 #endif
 
   NSOperatingSystemVersion version = [[NSProcessInfo processInfo] operatingSystemVersion];
-  RCTAssert(version.majorVersion == 8 || version.minorVersion == 3, @"Tests should be run on iOS 8.3, found %zd.%zd.%zd", version.majorVersion, version.minorVersion, version.patchVersion);
+  RCTAssert(version.majorVersion == 8 || version.minorVersion >= 3, @"Tests should be run on iOS 8.3+, found %zd.%zd.%zd", version.majorVersion, version.minorVersion, version.patchVersion);
   _runner = RCTInitRunnerForApp(@"Examples/UIExplorer/UIExplorerIntegrationTests/js/IntegrationTestsApp", nil);
 }
 
diff --git a/Examples/UIExplorer/UIExplorerIntegrationTests/UIExplorerSnapshotTests.m b/Examples/UIExplorer/UIExplorerIntegrationTests/UIExplorerSnapshotTests.m
index 1eb3110ec..cb5d1771f 100644
--- a/Examples/UIExplorer/UIExplorerIntegrationTests/UIExplorerSnapshotTests.m
+++ b/Examples/UIExplorer/UIExplorerIntegrationTests/UIExplorerSnapshotTests.m
@@ -32,11 +32,12 @@
 
 - (void)setUp
 {
-#ifdef __LP64__
-  RCTAssert(!__LP64__, @"Snapshot tests should be run on 32-bit device simulators (e.g. iPhone 5)");
+#if __LP64__
+  RCTAssert(NO, @"Tests should be run on 32-bit device simulators (e.g. iPhone 5)");
 #endif
-  NSString *version = [[UIDevice currentDevice] systemVersion];
-  RCTAssert([version isEqualToString:@"8.3"], @"Snapshot tests should be run on iOS 8.3, found %@", version);
+
+  NSOperatingSystemVersion version = [[NSProcessInfo processInfo] operatingSystemVersion];
+  RCTAssert(version.majorVersion == 8 || version.minorVersion >= 3, @"Snapshot tests should be run on iOS 8.3+, found %zd.%zd.%zd", version.majorVersion, version.minorVersion, version.patchVersion);
   _runner = RCTInitRunnerForApp(@"Examples/UIExplorer/UIExplorerApp.ios", nil);
   _runner.recordMode = NO;
 }
diff --git a/Examples/UIExplorer/UIExplorerIntegrationTests/js/LayoutEventsTest.js b/Examples/UIExplorer/UIExplorerIntegrationTests/js/LayoutEventsTest.js
index 0e16555f0..0333baf6c 100644
--- a/Examples/UIExplorer/UIExplorerIntegrationTests/js/LayoutEventsTest.js
+++ b/Examples/UIExplorer/UIExplorerIntegrationTests/js/LayoutEventsTest.js
@@ -51,8 +51,7 @@ var LayoutEventsTest = React.createClass({
       () => {
         debug('layout animation done.');
         this.checkLayout(this.addWrapText);
-      },
-      (error) => { throw new Error(JSON.stringify(error)); }
+      }
     );
     this.setState({viewStyle: {margin: 60}});
   },
diff --git a/Examples/UIExplorer/UIExplorerUnitTests/RCTBridgeTests.m b/Examples/UIExplorer/UIExplorerUnitTests/RCTBridgeTests.m
index 60f41747b..cca4fb016 100644
--- a/Examples/UIExplorer/UIExplorerUnitTests/RCTBridgeTests.m
+++ b/Examples/UIExplorer/UIExplorerUnitTests/RCTBridgeTests.m
@@ -170,7 +170,7 @@ RCT_EXPORT_MODULE(TestModule)
 }
 
 RCT_EXPORT_METHOD(testMethod:(NSInteger)integer
-                  number:(NSNumber *)number
+                  number:(nonnull NSNumber *)number
                   string:(NSString *)string
                   dictionary:(NSDictionary *)dict
                   callback:(RCTResponseSenderBlock)callback)
diff --git a/Libraries/Animation/LayoutAnimation.js b/Libraries/Animation/LayoutAnimation.js
index d435f431f..e0e0fdae4 100644
--- a/Libraries/Animation/LayoutAnimation.js
+++ b/Libraries/Animation/LayoutAnimation.js
@@ -69,9 +69,11 @@ type Config = {
   delete?: Anim;
 }
 
-function configureNext(config: Config, onAnimationDidEnd?: Function, onError?: Function) {
+function configureNext(config: Config, onAnimationDidEnd?: Function) {
   configChecker({config}, 'config', 'LayoutAnimation.configureNext');
-  RCTUIManager.configureNextLayoutAnimation(config, onAnimationDidEnd, onError);
+  RCTUIManager.configureNextLayoutAnimation(
+    config, onAnimationDidEnd || function() {}, function() { /* unused */ }
+  );
 }
 
 function create(duration: number, type, creationProp): Config {
diff --git a/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js b/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
index 72e75f813..f6a8bddc7 100644
--- a/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
+++ b/Libraries/JavaScriptAppEngine/System/JSTimers/JSTimers.js
@@ -47,7 +47,7 @@ var JSTimers = {
       return func.apply(undefined, args);
     };
     JSTimersExecution.types[freeIndex] = JSTimersExecution.Type.setTimeout;
-    RCTTiming.createTimer(newID, duration, Date.now(), /** recurring */ false);
+    RCTTiming.createTimer(newID, duration || 0, Date.now(), /** recurring */ false);
     return newID;
   },
 
@@ -63,7 +63,7 @@ var JSTimers = {
       return func.apply(undefined, args);
     };
     JSTimersExecution.types[freeIndex] = JSTimersExecution.Type.setInterval;
-    RCTTiming.createTimer(newID, duration, Date.now(), /** recurring */ true);
+    RCTTiming.createTimer(newID, duration || 0, Date.now(), /** recurring */ true);
     return newID;
   },