diff --git a/run-windows11.py b/run-windows11.py
index 5471bfc..504373f 100755
--- a/run-windows11.py
+++ b/run-windows11.py
@@ -138,7 +138,8 @@ Environment variables:
   WIN11_VM_UEFI_VARS    OVMF variable-store template path (auto-detected if unset)
   WIN11_VM_QEMU_CONFIG  QEMU config template passed to -readconfig
                         (default: qemu/windows11.ini)
-  WIN11_VM_DISPLAY      QEMU display backend (default: cocoa on macOS, gtk elsewhere)
+  WIN11_VM_DISPLAY      QEMU display backend (default: cocoa,zoom-to-fit=on on macOS,
+                        gtk elsewhere)
 """)
 
 
@@ -371,8 +372,11 @@ if installing:
              "-b", str(base_image), str(disk_image), disk_size])
     print(f"Created Windows 11 system disk: {disk_image}")
 
+# cocoa does not scale the guest by default, so the low-resolution installer
+# screen looks tiny on a Retina display; zoom-to-fit stretches it to the window,
+# as UTM does.
 display_backend = env("WIN11_VM_DISPLAY") or (
-    "cocoa" if platform.system() == "Darwin" else "gtk")
+    "cocoa,zoom-to-fit=on" if platform.system() == "Darwin" else "gtk")
 
 # Most of the VM definition lives in the QEMU config template; fill in the
 # file paths and hand the rendered file to QEMU with -readconfig.