diff --git a/Signal/src/util/UIViewController+CameraPermissions.m b/Signal/src/util/UIViewController+CameraPermissions.m
index 59fba0f6c..58abd9685 100644
--- a/Signal/src/util/UIViewController+CameraPermissions.m
+++ b/Signal/src/util/UIViewController+CameraPermissions.m
@@ -19,6 +19,7 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)ows_askForCameraPermissions:(void (^)())permissionsGrantedCallback
                     failureCallback:(nullable void (^)())failureCallback
 {
+    // Avoid nil tests below.
     if (!failureCallback) {
         failureCallback = ^{
         };