diff --git a/alt-tab-macos/api-wrappers/CGWindow.swift b/alt-tab-macos/api-wrappers/CGWindow.swift
index ed8b47f8..58d1887d 100644
--- a/alt-tab-macos/api-wrappers/CGWindow.swift
+++ b/alt-tab-macos/api-wrappers/CGWindow.swift
@@ -8,6 +8,15 @@ extension CGWindow {
         return CGWindowListCopyWindowInfo([.excludeDesktopElements, option], kCGNullWindowID) as! [CGWindow]
     }
 
+    static func isMissionControlActive() -> Bool {
+        // when Mission Control is active, the Dock process spawns some windows. We observe this side-effect and infer
+        for window in windows(.optionOnScreenOnly) {
+            guard window.ownerName() == "Dock" else { continue }
+            return true
+        }
+        return false
+    }
+
     // workaround: filtering this criteria seems to remove non-windows UI elements
     func isNotMenubarOrOthers() -> Bool {
         return layer() == 0
diff --git a/alt-tab-macos/ui/App.swift b/alt-tab-macos/ui/App.swift
index 042d42b0..fdbc9acf 100644
--- a/alt-tab-macos/ui/App.swift
+++ b/alt-tab-macos/ui/App.swift
@@ -82,7 +82,7 @@ class App: NSApplication, NSApplicationDelegate, NSWindowDelegate {
         if isFirstSummon {
             debugPrint("showUiOrCycleSelection: isFirstSummon")
             isFirstSummon = false
-            if Windows.listRecentlyUsedFirst.count == 0 {
+            if Windows.listRecentlyUsedFirst.count == 0 || CGWindow.isMissionControlActive() {
                 appIsBeingUsed = false
                 isFirstSummon = true
                 return
@@ -112,6 +112,7 @@ class App: NSApplication, NSApplicationDelegate, NSWindowDelegate {
 
     func focusSelectedWindow(_ window: Window?) {
         hideUi()
+        guard !CGWindow.isMissionControlActive() else { return }
         window?.focus()
     }
 }