diff --git a/lisp/files.el b/lisp/files.el
index 9b1fc09fcfa..22313b71635 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -8742,6 +8742,9 @@ arguments as the running Emacs)."
 			  (file-in-directory-p 0 1)
 			  (make-symbolic-link 0 1)
 			  (add-name-to-file 0 1)
+                          ;; `get-file-buffer' shall simply run the
+                          ;; original function.
+                          (get-file-buffer)
                           ;; These file-notify-* operations take a
                           ;; descriptor.
                           (file-notify-rm-watch)
diff --git a/test/lisp/files-tests.el b/test/lisp/files-tests.el
index 55011cd461a..822e031e0bf 100644
--- a/test/lisp/files-tests.el
+++ b/test/lisp/files-tests.el
@@ -401,7 +401,8 @@ be $HOME."
   (append '("foo" "$foo" "~foo")
           ;; No amount of quoting will allow creation of a file name
           ;; with an embedded '*' on MS-Windows and MS-DOS.
-          (if (not (memq system-type '(windows-nt ms-dos))) '("foo*bar")))
+          (if (not (memq system-type '(windows-nt ms-dos)))
+              '("foo*bar" "foo?bar")))
   "Prefixes to be tested for `file-name-non-special' tests.")
 
 (ert-deftest files-tests-file-name-non-special--subprocess ()
@@ -696,6 +697,8 @@ unquoted file names."
       (tmpdir nospecial-dir t)
     (should-error (directory-files-and-attributes nospecial-dir))))
 
+(defvar w32-downcase-file-names)
+
 (ert-deftest files-tests-directory-files-recursively-w32 ()
   "Test MS-Windows specific features of `directory-files-recursively'."
   (skip-unless (eq system-type 'windows-nt))
@@ -1054,12 +1057,16 @@ unquoted file names."
 (ert-deftest files-tests-file-name-non-special-get-file-buffer ()
   ;; Make sure these buffers don't exist.
   (files-tests--with-temp-non-special (tmpfile nospecial)
+    (find-file-noselect nospecial)
     (let ((fbuf (get-file-buffer nospecial)))
-      (if fbuf (kill-buffer fbuf))
+      (should (get-file-buffer nospecial))
+      (kill-buffer fbuf)
       (should-not (get-file-buffer nospecial))))
   (files-tests--with-temp-non-special-and-file-name-handler (tmpfile nospecial)
+    (find-file-noselect nospecial)
     (let ((fbuf (get-file-buffer nospecial)))
-      (if fbuf (kill-buffer fbuf))
+      (should (get-file-buffer nospecial))
+      (kill-buffer fbuf)
       (should-not (get-file-buffer nospecial)))))
 
 (ert-deftest files-tests-file-name-non-special-insert-directory ()