diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 3008a056a2..d98eade4a3 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -499,6 +499,15 @@ NSUInteger QCocoaWindow::windowStyleMask(Qt::WindowFlags flags)
     // Select base window type. Note that the value of NSBorderlessWindowMask is 0.
     NSUInteger styleMask = (frameless || !resizable) ? NSWindowStyleMaskBorderless : NSWindowStyleMaskResizable;
 
+    // Patch: allow creating panels floating on all spaces in macOS.
+    // If you call "setCollectionBehavior:NSWindowCollectionBehaviorFullScreenAuxiliary" before
+    // setting the "NSWindowStyleMaskNonactivatingPanel" bit in the style mask it won't work after that.
+    // So we need a way to set that bit before Qt sets collection behavior the way it does.
+    QVariant nonactivatingPanelMask = window()->property("_td_macNonactivatingPanelMask");
+    if (nonactivatingPanelMask.isValid() && nonactivatingPanelMask.toBool()) {
+        styleMask |= NSWindowStyleMaskNonactivatingPanel;
+    }
+
     if (frameless) {
         // No further customizations for frameless since there are no window decorations.
     } else if (flags & Qt::CustomizeWindowHint) {