diff --git a/ReactAndroid/src/main/java/com/facebook/react/ReactPackage.java b/ReactAndroid/src/main/java/com/facebook/react/ReactPackage.java
index 527db0ace2e544..7bf8569d7bc00c 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/ReactPackage.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/ReactPackage.java
@@ -34,10 +34,12 @@ public interface ReactPackage {
    * @param reactContext react application context that can be used to create modules
    * @return list of native modules to register with the newly created catalyst instance
    */
+  @Nonnull
   List<NativeModule> createNativeModules(@Nonnull ReactApplicationContext reactContext);
 
   /**
    * @return a list of view managers that should be registered with {@link UIManagerModule}
    */
+  @Nonnull
   List<ViewManager> createViewManagers(@Nonnull ReactApplicationContext reactContext);
 }
diff --git a/ReactAndroid/src/main/java/com/facebook/react/modules/core/DeviceEventManagerModule.java b/ReactAndroid/src/main/java/com/facebook/react/modules/core/DeviceEventManagerModule.java
index 56109af8af0ec1..c78527208ccbc0 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/modules/core/DeviceEventManagerModule.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/modules/core/DeviceEventManagerModule.java
@@ -7,6 +7,7 @@
 
 package com.facebook.react.modules.core;
 
+import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import android.net.Uri;
@@ -27,7 +28,7 @@
 public class DeviceEventManagerModule extends ReactContextBaseJavaModule {
   public static final String NAME = "DeviceEventManager";
   public interface RCTDeviceEventEmitter extends JavaScriptModule {
-    void emit(String eventName, @Nullable Object data);
+    void emit(@Nonnull String eventName, @Nullable Object data);
   }
 
   private final Runnable mInvokeDefaultBackPressRunnable;