diff --git a/app/src/main/java/acr/browser/lightning/react/Observable.java b/app/src/main/java/acr/browser/lightning/react/Observable.java
index 8169625..89dbef5 100644
--- a/app/src/main/java/acr/browser/lightning/react/Observable.java
+++ b/app/src/main/java/acr/browser/lightning/react/Observable.java
@@ -21,12 +21,12 @@ public class Observable<T> {
 
     private static final String TAG = Observable.class.getSimpleName();
 
-    @NonNull private Action<T> mAction;
+    @NonNull private final Action<T> mAction;
     @Nullable private Executor mSubscriber;
     @Nullable private Executor mObserver;
     @NonNull private final Executor mDefault;
 
-    public Observable(@NonNull Action<T> action) {
+    private Observable(@NonNull Action<T> action) {
         mAction = action;
         Looper looper = Looper.myLooper();
         Preconditions.checkNonNull(looper);
@@ -111,7 +111,7 @@ public class Observable<T> {
                     public void onComplete() {
                         if (!mOnCompleteExecuted) {
                             mOnCompleteExecuted = true;
-                            executeOnObserverThread(new OnCompleteRunnable(subscription));
+                            executeOnObserverThread(new OnCompleteRunnable<>(subscription));
                         } else {
                             Log.e(TAG, "onComplete called more than once");
                             throw new RuntimeException("onComplete called more than once");
@@ -121,7 +121,7 @@ public class Observable<T> {
                     @Override
                     public void onNext(final T item) {
                         if (!mOnCompleteExecuted) {
-                            executeOnObserverThread(new OnNextRunnable(subscription, item));
+                            executeOnObserverThread(new OnNextRunnable<>(subscription, item));
                         } else {
                             Log.e(TAG, "onComplete has been already called, onNext should not be called");
                             throw new RuntimeException("onNext should not be called after onComplete has been called");
@@ -149,10 +149,10 @@ public class Observable<T> {
         }
     }
 
-    private static class OnCompleteRunnable implements Runnable {
-        private final Subscription subscription;
+    private static class OnCompleteRunnable<T> implements Runnable {
+        private final Subscription<T> subscription;
 
-        public OnCompleteRunnable(Subscription subscription) {this.subscription = subscription;}
+        public OnCompleteRunnable(Subscription<T> subscription) {this.subscription = subscription;}
 
         @Override
         public void run() {
@@ -160,7 +160,7 @@ public class Observable<T> {
         }
     }
 
-    private class OnNextRunnable implements Runnable {
+    private static class OnNextRunnable<T> implements Runnable {
         private final Subscription<T> subscription;
         private final T item;
 
diff --git a/build.gradle b/build.gradle
index 19694a3..eccee5b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -12,8 +12,6 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
-        maven {
-            url 'https://oss.sonatype.org/content/repositories/snapshots/'
-        }
+        mavenCentral()
     }
 }