diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 63ccd05a26..18c1e509ca 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2483,6 +2483,7 @@ tramp-test10-write-region

 	    ;; Write empty string.  Used for creation of temprorary files.
 	    ;; Since Emacs 27.1.
+            (tramp--test-instrument-test-case 10
 	    (when (fboundp 'make-empty-file)
 	      (with-no-warnings
 		(should-error
@@ -2492,7 +2493,7 @@ tramp-test10-write-region
 		(make-empty-file tmp-name)
 		(with-temp-buffer
 		  (insert-file-contents tmp-name)
-		  (should (string-equal (buffer-string) "")))))
+		  (should (string-equal (buffer-string) ""))))))

 	    ;; Write partly.
 	    (with-temp-buffer