diff --git a/cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java b/cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java
index 39582b37..cb41d077 100644
--- a/cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java
+++ b/cameraview/src/main/java/com/otaliastudios/cameraview/CameraView.java
@@ -1189,10 +1189,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      *
      * @param cameraListener a listener for events.
      */
-    public void addCameraListener(@Nullable CameraListener cameraListener) {
-        if (cameraListener != null) {
-            mListeners.add(cameraListener);
-        }
+    public void addCameraListener(@NonNull CameraListener cameraListener) {
+        mListeners.add(cameraListener);
     }
 
 
@@ -1201,10 +1199,8 @@ public class CameraView extends FrameLayout implements LifecycleObserver {
      *
      * @param cameraListener a listener for events.
      */
-    public void removeCameraListener(@Nullable CameraListener cameraListener) {
-        if (cameraListener != null) {
-            mListeners.remove(cameraListener);
-        }
+    public void removeCameraListener(@NonNull CameraListener cameraListener) {
+        mListeners.remove(cameraListener);
     }
 
 
diff --git a/docs/_posts/2018-12-20-preview-size.md b/docs/_posts/2018-12-20-preview-size.md
index a81fdce9..4573f591 100644
--- a/docs/_posts/2018-12-20-preview-size.md
+++ b/docs/_posts/2018-12-20-preview-size.md
@@ -86,3 +86,4 @@ After the preview size is determined, if it has changed since list time, the `Ca
 another call to `onMeasure` so the `WRAP_CONTENT` magic can take place.
 
 To understand how SizeSelectors work and the available utilities, please read the [Capture Size](capture-size.html) document.
+