diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 9930a2c9e1..3d5949b033 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -5288,18 +5288,26 @@ tramp--test-check-files
 		  (setenv "PS1")
 		  (with-temp-buffer
 		    (should (zerop (process-file "env" nil t nil)))
-		    (goto-char (point-min))
-		    (should
-		     (re-search-forward
-                      ;; We must use proper encoding on macOS.  See
-                      ;; Bug#36940.
-                      (funcall
-	               (if (eq coding-system-for-read 'utf-8-hfs)
-                           'ucs-normalize-HFS-NFD-string 'identity)
-		       (format
-		        "^%s=%s$"
-		        (regexp-quote envvar)
-		        (regexp-quote (getenv envvar)))))))))))
+                    (tramp--test-message
+                     "coding-sytem: `%s' `%s'"
+                     coding-system-for-read coding-system-for-write )
+                    (tramp--test-message "search: `%s'" (getenv envvar))
+                    ;; We must use proper encoding on macOS.  See
+                    ;; Bug#36940.
+                    (let ((system-type 'gnu/linux)
+                          (coding-system-for-read 'no-conversion)
+                          (coding-system-for-write 'no-conversion))
+                      (tramp--test-message
+                       "search: `%s'"
+                       (ucs-normalize-HFS-NFD-string (getenv envvar)))
+                      (tramp--test-message "buffer: `%s'" (buffer-string))
+		      (goto-char (point-min))
+		      (should
+		       (re-search-forward
+		        (format
+		         "^%s=%s$"
+		         (regexp-quote envvar)
+		         (regexp-quote (getenv envvar)))))))))))

 	;; Cleanup.
 	(ignore-errors (delete-directory tmp-name1 'recursive))