diff --git a/src/osx/cocoa/nonownedwnd.mm b/src/osx/cocoa/nonownedwnd.mm
index 560bdd5d95..777b0bafb4 100644
--- a/src/osx/cocoa/nonownedwnd.mm
+++ b/src/osx/cocoa/nonownedwnd.mm
@@ -492,6 +492,15 @@ extern int wxOSXGetIdFromSelector(SEL action );
     wxNonOwnedWindowCocoaImpl* windowimpl = [window WX_implementation];
     if ( windowimpl )
     {
+        // See windowDidResignKey: -- we emulate corresponding focus set
+        // event for the first responder here as well:
+        NSView *firstResponder = [window firstResponder];
+        wxWidgetCocoaImpl *focused = firstResponder
+                ? (wxWidgetCocoaImpl*)wxWidgetImpl::FindFromWXWidget(wxOSXGetViewFromResponder(firstResponder))
+                : NULL;
+        if ( focused )
+            focused->DoNotifyFocusSet();
+
         wxNonOwnedWindow* wxpeer = windowimpl->GetWXPeer();
         if ( wxpeer )
             wxpeer->HandleActivated(0, true);
@@ -508,10 +517,17 @@ extern int wxOSXGetIdFromSelector(SEL action );
         if ( wxpeer )
         {
             wxpeer->HandleActivated(0, false);
-            // as for wx the deactivation also means losing focus we
-            // must trigger this manually
-            [window makeFirstResponder:nil];
-            
+
+            // As for wx the deactivation also means losing focus, we
+            // must emulate focus events _without_ resetting first responder
+            // (because that would subtly break other things in Cocoa/macOS):
+            NSView *firstResponder = [window firstResponder];
+            wxWidgetCocoaImpl *focused = firstResponder
+                    ? (wxWidgetCocoaImpl*)wxWidgetImpl::FindFromWXWidget(wxOSXGetViewFromResponder(firstResponder))
+                    : NULL;
+            if ( focused )
+                focused->DoNotifyFocusLost();
+
             // TODO Remove if no problems arise with Popup Windows
 #if 0
             // Needed for popup window since the firstResponder
diff --git a/src/osx/cocoa/window.mm b/src/osx/cocoa/window.mm
index 267f3942bd..e1375beee7 100644
--- a/src/osx/cocoa/window.mm
+++ b/src/osx/cocoa/window.mm
@@ -71,7 +71,24 @@ NSView* GetFocusedViewInWindow( NSWindow* keyWindow )
 
 WXWidget wxWidgetImpl::FindFocus()
 {
-    return GetFocusedViewInWindow( [NSApp keyWindow] );;
+    NSWindow *key = [NSApp keyWindow];
+    if ( key == nil )
+    {
+        // Application's keyWindow property may still not be updated and be
+        // nil when windowDidBecomeKey: is called and even if the
+        // just-activated's window isKeyWindow already returns YES. To get
+        // accurate information about where the focus is at all times, we have
+        // to explicitly check all application windos as well:
+        for ( NSWindow *w in [NSApp windows] )
+        {
+            if ( [w isKeyWindow] )
+            {
+                key = w;
+                break;
+            }
+        }
+    }
+    return key ? GetFocusedViewInWindow(key) : nil;
 }
 
 wxWidgetImpl* wxWidgetImpl::FindBestFromWXWidget(WXWidget control)