diff --git a/MVMCoreUI/Behaviors/ScreenBrightnessModifierBehavior.swift b/MVMCoreUI/Behaviors/ScreenBrightnessModifierBehavior.swift
index 03464841..b6ea9f6d 100644
--- a/MVMCoreUI/Behaviors/ScreenBrightnessModifierBehavior.swift
+++ b/MVMCoreUI/Behaviors/ScreenBrightnessModifierBehavior.swift
@@ -27,7 +27,7 @@ public class ScreenBrightnessModifierBehavior: PageVisibilityBehavior {
     //MARK:- Behavior
     
     func changeScreenBrightness() {
-        if originalScreenBrightness != nil { return }
+        guard originalScreenBrightness == nil else { return }
         originalScreenBrightness = UIScreen.main.brightness
         UIScreen.main.brightness = screenBrightness
         NotificationCenter.default.addObserver(self, selector: #selector(willResignActive), name: UIApplication.willResignActiveNotification, object: nil)