diff --git a/tools/test_uvk5_supervisor.py b/tools/test_uvk5_supervisor.py
index d416c7c..67a4a7e 100644
--- a/tools/test_uvk5_supervisor.py
+++ b/tools/test_uvk5_supervisor.py
@@ -299,3 +299,23 @@ class TestRecoversFromAnExternalKill(unittest.TestCase):
 
 if __name__ == "__main__":
     unittest.main()
+
+
+class TestLauncherPrefersTheWorkingCopy(unittest.TestCase):
+    """A restart must not look like the page's installs vanished."""
+
+    def test_the_script_lists_the_working_copy_before_the_original(self):
+        import os as _os
+        path = _os.path.join(_os.path.dirname(_os.path.abspath(__file__)),
+                            "..", "work", "run-webui.ps1")
+        if not _os.path.exists(path):
+            self.skipTest("work/run-webui.ps1 is not in this checkout")
+        with open(path, encoding="utf-8") as fh:
+            text = fh.read()
+        # the working copy the page edits comes before the file it was first pointed at
+        working = text.find("work\\firmware\\flash-current.img")
+        original = text.find("work\\user-flash.img")
+        self.assertNotEqual(working, -1, "the working copy is not in the list")
+        self.assertNotEqual(original, -1)
+        self.assertLess(working, original,
+                        "a restart would fall back to the original image")
diff --git a/tools/webui.py b/tools/webui.py
index 49732a7..5448225 100644
--- a/tools/webui.py
+++ b/tools/webui.py
@@ -975,7 +975,9 @@ def render_index(scale: int) -> str:
   <div class="fwbar">
     <label class="mini">flash image<input type="file" id="flashfile" accept=".img,.bin"></label>
     <span class="hint">the multi-system slots live in the external flash;
-    write a .bin into one, then press Multiboot</span>
+    write a .bin into one, then press Multiboot. Edits go to a working copy of the image
+    (the file named above), so the one you loaded is never modified — and a restart keeps
+    that copy rather than reverting to the original</span>
   </div>
   <table id="slottable"><tbody></tbody></table>
   </details>
diff --git a/work/run-webui.ps1 b/work/run-webui.ps1
index 29b33f6..52f3475 100644
--- a/work/run-webui.ps1
+++ b/work/run-webui.ps1
@@ -46,7 +46,12 @@ if ($Status) { $common += @('--status-addr', $Status) }
 
 if (-not $Kernel -and $env:ELF) { $Kernel = $env:ELF }
 if (-not $Flash) {
-    $candidates = @($env:UVK5_FLASH_IMAGE, 'work\user-flash.img', 'assets\flash.img')
+    # The page edits a working copy (webui copies the image before its first write, so a
+    # real calibration dump is never touched). Preferring it here means a restart keeps
+    # whatever was installed through the page, instead of silently falling back to the
+    # file it was first pointed at and looking like the install vanished.
+    $candidates = @($env:UVK5_FLASH_IMAGE, 'work\firmware\flash-current.img',
+                    'work\user-flash.img', 'assets\flash.img')
     foreach ($candidate in $candidates) {
         if ($candidate -and (Test-Path $candidate)) { $Flash = $candidate; break }
     }