diff --git a/src/corelib/io/qfilesystemengine_win.cpp b/src/corelib/io/qfilesystemengine_win.cpp
index d1a197698e5..9e009a05e7d 100644
--- a/src/corelib/io/qfilesystemengine_win.cpp
+++ b/src/corelib/io/qfilesystemengine_win.cpp
@@ -1180,7 +1180,7 @@ bool QFileSystemEngine::createDirectory(const QFileSystemEntry &entry, bool crea
     // mkpath should return true, if the directory already exists, mkdir false.
     if (!createParents)
         return false;
-    if (lastError == ERROR_ALREADY_EXISTS)
+    if (lastError == ERROR_ALREADY_EXISTS || lastError == ERROR_ACCESS_DENIED)
         return isDirPath(dirName, nullptr);
 
     return createDirectoryWithParents(dirName, false);
diff --git a/tests/auto/corelib/io/qdir/tst_qdir.cpp b/tests/auto/corelib/io/qdir/tst_qdir.cpp
index 3675e45f838..7e77e22f67e 100644
--- a/tests/auto/corelib/io/qdir/tst_qdir.cpp
+++ b/tests/auto/corelib/io/qdir/tst_qdir.cpp
@@ -466,6 +466,11 @@ void tst_QDir::makedirReturnCode()
     QVERIFY(!QDir::current().mkdir(dirName)); // calling mkdir on an existing dir will fail.
     QVERIFY(QDir::current().mkpath(dirName)); // calling mkpath on an existing dir will pass
 
+#ifdef Q_OS_WIN
+    // the next line specifically targets Windows, see QTBUG-85997
+    QVERIFY(QDir().mkpath(QDir::rootPath())); // calling mkpath on an existing drive name will pass
+#endif
+
     // Remove the directory and create a file with the same path
     QDir::current().rmdir(dirName);
     QVERIFY(!f.exists());