diff --git a/apps/openmw/mwgui/windowmanagerimp.cpp b/apps/openmw/mwgui/windowmanagerimp.cpp
index 42e2cc54d7..4265540839 100644
--- a/apps/openmw/mwgui/windowmanagerimp.cpp
+++ b/apps/openmw/mwgui/windowmanagerimp.cpp
@@ -2079,7 +2079,10 @@ namespace MWGui
     void WindowManager::togglePostProcessorHud()
     {
         if (!MWBase::Environment::get().getWorld()->getPostProcessor()->isEnabled())
+        {
+            messageBox("Postprocessor is not enabled.");
             return;
+        }
 
         bool visible = mPostProcessorHud->isVisible();