diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 309f225a935..8a1aee3ad4c 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -526,9 +526,11 @@ NSUInteger QCocoaWindow::windowStyleMask(Qt::WindowFlags flags)
     // working (for example minimizing frameless windows, or resizing
     // windows that don't have zoom or fullscreen titlebar buttons).
     styleMask |= NSWindowStyleMaskClosable
-               | NSWindowStyleMaskResizable
                | NSWindowStyleMaskMiniaturizable;
 
+    if (type != Qt::Popup) // We only care about popups exactly.
+        styleMask |= NSWindowStyleMaskResizable;
+
     if (type == Qt::Tool)
         styleMask |= NSWindowStyleMaskUtilityWindow;