diff --git a/guix/serialization.scm b/guix/serialization.scm
index e6ae2fc30..77a54f904 100644
--- a/guix/serialization.scm
+++ b/guix/serialization.scm
@@ -18,6 +18,8 @@
 
 (define-module (guix serialization)
   #:use-module (guix combinators)
+  #:use-module ((guix build syscalls)
+                #:select (scandir/utf-8))
   #:use-module (rnrs bytevectors)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-26)
@@ -285,8 +287,11 @@ result of 'lstat'; exclude entries for which SELECT? does not return true."
               ;; 'scandir' defaults to 'string-locale<?' to sort files, but
               ;; this happens to be case-insensitive (at least in 'en_US'
               ;; locale on libc 2.18.)  Conversely, we want files to be
-              ;; sorted in a case-sensitive fashion.
-              (scandir f (negate (cut member <> '("." ".."))) string<?)))
+              ;; sorted in a case-sensitive fashion.  Also, always decode file
+              ;; names as UTF-8.
+              (scandir/utf-8
+               f (negate (cut member <> '("." "..")))
+                             string<?)))
          (for-each (lambda (e)
                      (let* ((f (string-append f "/" e))
                             (s (lstat f)))
diff --git a/tests/nar.scm b/tests/nar.scm
index 61646db96..d2eae65c4 100644
--- a/tests/nar.scm
+++ b/tests/nar.scm
@@ -25,6 +25,8 @@
                 #:select (open-sha256-port open-sha256-input-port))
   #:use-module ((guix packages)
                 #:select (base32))
+  #:use-module ((guix utils)
+                #:select (call-with-temporary-directory))
   #:use-module (rnrs bytevectors)
   #:use-module (rnrs io ports)
   #:use-module (srfi srfi-1)
@@ -272,6 +274,36 @@
       (lambda ()
         (rmdir input)))))
 
+(unless (equal? "UTF-8" (fluid-ref %default-port-encoding))
+  (test-skip 1))
+(test-assert "write-file + restore-file, UTF-8 file names"
+  (let* ((output %test-dir)
+         (nar    (string-append output ".nar"))
+         (locale (setlocale LC_ALL)))
+    (dynamic-wind
+      (lambda () #t)
+      (lambda ()
+        (call-with-temporary-directory
+         (lambda (input)
+           (call-with-output-file (string-append input "/α")
+             (const #t))
+           (call-with-output-file (string-append input "/λ")
+             (const #t))
+           (dynamic-wind
+             (const #f)
+             (lambda ()
+               (setlocale LC_ALL "C")
+               (call-with-output-file nar
+                 (cut write-file input <>)))
+             (lambda ()
+               (setlocale LC_ALL locale)))
+           (call-with-input-file nar
+             (cut restore-file <> output))
+           (file-tree-equal? input output))))
+      (lambda ()
+        (false-if-exception (delete-file nar))
+        (false-if-exception (rm-rf output))))))
+
 ;; 'restore-file-set' depends on 'open-sha256-input-port', which in turn
 ;; relies on a Guile 2.0.10+ feature.
 (test-skip (if (false-if-exception