diff --git a/native/windows/src/filesystem.cc b/native/windows/src/filesystem.cc
index edecb1978a..c539166d34 100644
--- a/native/windows/src/filesystem.cc
+++ b/native/windows/src/filesystem.cc
@@ -473,6 +473,9 @@ static void dispose(HANDLE handle, const std::wstring& path) {
   require(GetFileInformationByHandleEx(handle, FileBasicInfo, &info, sizeof(info)), "Read cleanup attributes failed", path);
   if ((info.FileAttributes & FILE_ATTRIBUTE_READONLY) != 0) {
     info.FileAttributes &= ~FILE_ATTRIBUTE_READONLY;
+    // Zero means "leave attributes unchanged" to FileBasicInfo. A file whose
+    // sole attribute was READONLY needs NORMAL to actually clear that marker.
+    if (info.FileAttributes == 0) info.FileAttributes = FILE_ATTRIBUTE_NORMAL;
     require(SetFileInformationByHandle(handle, FileBasicInfo, &info, sizeof(info)), "Clear owned readonly attribute failed", path);
   }
   FILE_DISPOSITION_INFO deletion{TRUE};
diff --git a/scripts/verify-windows-native.mjs b/scripts/verify-windows-native.mjs
index b121b714bd..5b0729b01f 100644
--- a/scripts/verify-windows-native.mjs
+++ b/scripts/verify-windows-native.mjs
@@ -588,7 +588,7 @@ process.stdout.write(JSON.stringify({executable:basename(process.execPath),abiVe
           "-NoProfile",
           "-NonInteractive",
           "-Command",
-          "$ErrorActionPreference='Stop'; $items=ConvertFrom-Json -InputObject $env:REA_TEST_READONLY_CHILDREN; @($items | ForEach-Object { [IO.File]::SetAttributes($_,[IO.FileAttributes]([int][IO.File]::GetAttributes($_) -bor 1)); $a=[int][IO.File]::GetAttributes($_); @{readonly=(($a -band 1) -ne 0); directory=(($a -band 16) -ne 0)} }) | ConvertTo-Json -Compress",
+          "$ErrorActionPreference='Stop'; $items=ConvertFrom-Json -InputObject $env:REA_TEST_READONLY_CHILDREN; @($items | ForEach-Object { $current=[int][IO.File]::GetAttributes($_); $next=if(($current -band 16) -ne 0){$current -bor 1}else{1}; [IO.File]::SetAttributes($_,[IO.FileAttributes]$next); $a=[int][IO.File]::GetAttributes($_); @{readonly=(($a -band 1) -ne 0); directory=(($a -band 16) -ne 0); onlyReadonly=($a -eq 1)} }) | ConvertTo-Json -Compress",
         ],
         {
           encoding: "utf8",
@@ -604,8 +604,8 @@ process.stdout.write(JSON.stringify({executable:basename(process.execPath),abiVe
       ),
     );
     assert.deepEqual(readonlyChildren, [
-      { readonly: true, directory: true },
-      { readonly: true, directory: false },
+      { readonly: true, directory: true, onlyReadonly: false },
+      { readonly: true, directory: false, onlyReadonly: true },
     ]);
   } catch (failure) {
     runtimeVerificationErrors.push(failure);
@@ -626,6 +626,7 @@ process.stdout.write(JSON.stringify({executable:basename(process.execPath),abiVe
   assert.equal(await readFile(sentinel, "utf8"), "preserve");
   report.controls.cleanupDoesNotTraverseJunctions = true;
   report.controls.readonlyRootAndChildrenRemoved = true;
+  report.controls.readonlyFileWithoutArchiveAttributeRemoved = true;
   const fixture = join(workspace, "tree.mjs");
   await writeFile(
     fixture,