diff --git a/gnu/build/accounts.scm b/gnu/build/accounts.scm
index 8687446aa6..c13e6f2e89 100644
--- a/gnu/build/accounts.scm
+++ b/gnu/build/accounts.scm
@@ -19,6 +19,7 @@
 (define-module (gnu build accounts)
   #:use-module (guix records)
   #:use-module (guix combinators)
+  #:use-module ((guix build syscalls) #:select (fdatasync))
   #:use-module (gnu system accounts)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
@@ -230,6 +231,14 @@ each field."
   ;; grab this lock with 'with-file-lock' when they access the databases.
   "/etc/.pwd.lock")
 
+(define-syntax-rule (catch-ENOSYS exp)
+  (catch 'system-error
+    (lambda () exp)
+    (lambda args
+      (if (= ENOSYS (system-error-errno args))
+          #f
+          (apply throw args)))))
+
 (define (database-writer file mode entry->string)
   (lambda* (entries #:optional (file-or-port file))
     "Write ENTRIES to FILE-OR-PORT.  When FILE-OR-PORT is a file name, write
@@ -249,9 +258,12 @@ to it atomically and set the appropriate permissions."
             (lambda ()
               (chmod port mode)
               (write-entries port)
-              (rename-file template file-or-port))
-            (lambda ()
+              (catch-ENOSYS (fdatasync port))
               (close-port port)
+              (rename-file template file-or-port))
+            (lambda ()
+              (unless (port-closed? port)
+                (close-port port))
               (when (file-exists? template)
                 (delete-file template))))))))