diff --git a/src/logic/Window.swift b/src/logic/Window.swift
index cdacfaff..fd1b84cb 100644
--- a/src/logic/Window.swift
+++ b/src/logic/Window.swift
@@ -146,7 +146,7 @@ class Window {
     }
 
     func toggleFullscreen() {
-        if canBeMinDeminOrFullscreened() {
+        if !canBeMinDeminOrFullscreened() {
             NSSound.beep()
             return
         }