diff --git a/gnu/build/activation.scm b/gnu/build/activation.scm
index 820e04d648..aa5b7031f1 100644
--- a/gnu/build/activation.scm
+++ b/gnu/build/activation.scm
@@ -19,11 +19,13 @@
 
 (define-module (gnu build activation)
   #:use-module (gnu system accounts)
+  #:use-module (gnu build accounts)
   #:use-module (gnu build linux-boot)
   #:use-module (guix build utils)
   #:use-module (ice-9 ftw)
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-26)
   #:export (activate-users+groups
             activate-user-home
@@ -43,35 +45,6 @@
 ;;;
 ;;; Code:
 
-(define (enumerate thunk)
-  "Return the list of values returned by THUNK until it returned #f."
-  (let loop ((entry  (thunk))
-             (result '()))
-    (if (not entry)
-        (reverse result)
-        (loop (thunk) (cons entry result)))))
-
-(define (current-users)
-  "Return the passwd entries for all the currently defined user accounts."
-  (setpw)
-  (enumerate getpwent))
-
-(define (current-groups)
-  "Return the group entries for all the currently defined user groups."
-  (setgr)
-  (enumerate getgrent))
-
-(define* (add-group name #:key gid password system?
-                    (log-port (current-error-port)))
-  "Add NAME as a user group, with the given numeric GID if specified."
-  ;; Use 'groupadd' from the Shadow package.
-  (format log-port "adding group '~a'...~%" name)
-  (let ((args `(,@(if gid `("-g" ,(number->string gid)) '())
-                ,@(if password `("-p" ,password) '())
-                ,@(if system? `("--system") '())
-                ,name)))
-    (zero? (apply system* "groupadd" args))))
-
 (define %skeleton-directory
   ;; Directory containing skeleton files for new accounts.
   ;; Note: keep the trailing '/' so that 'scandir' enters it.
@@ -117,172 +90,32 @@ owner-writable in HOME."
                     (make-file-writable target))))
               files)))
 
-(define* (add-user name group
-                   #:key uid comment home create-home?
-                   shell password system?
-                   (supplementary-groups '())
-                   (log-port (current-error-port)))
-  "Create an account for user NAME part of GROUP, with the specified
-properties.  Return #t on success."
-  (format log-port "adding user '~a'...~%" name)
-
-  (if (and uid (zero? uid))
-
-      ;; 'useradd' fails with "Cannot determine your user name" if the root
-      ;; account doesn't exist.  Thus, for bootstrapping purposes, create that
-      ;; one manually.
-      (let ((home (or home "/root")))
-        (call-with-output-file "/etc/shadow"
-          (cut format <> "~a::::::::~%" name))
-        (call-with-output-file "/etc/passwd"
-          (cut format <> "~a:x:~a:~a:~a:~a:~a~%"
-               name "0" "0" comment home shell))
-        (chmod "/etc/shadow" #o600)
-        (copy-account-skeletons home)
-        (chmod home #o700)
-        #t)
-
-      ;; Use 'useradd' from the Shadow package.
-      (let ((args `(,@(if uid `("-u" ,(number->string uid)) '())
-                    "-g" ,(if (number? group) (number->string group) group)
-                    ,@(if (pair? supplementary-groups)
-                          `("-G" ,(string-join supplementary-groups ","))
-                          '())
-                    ,@(if comment `("-c" ,comment) '())
-                    ,@(if home `("-d" ,home) '())
-
-                    ;; Home directories of non-system accounts are created by
-                    ;; 'activate-user-home'.
-                    ,@(if (and home create-home? system?
-                               (not (file-exists? home)))
-                          '("--create-home")
-                          '())
-
-                    ,@(if shell `("-s" ,shell) '())
-                    ,@(if password `("-p" ,password) '())
-                    ,@(if system? '("--system") '())
-                    ,name)))
-        (and (zero? (apply system* "useradd" args))
-             (begin
-               ;; Since /etc/skel is a link to a directory in the store where
-               ;; all files have the writable bit cleared, and since 'useradd'
-               ;; preserves permissions when it copies them, explicitly make
-               ;; them writable.
-               (make-skeletons-writable home)
-               #t)))))
-
-(define* (modify-user name group
-                      #:key uid comment home create-home?
-                      shell password system?
-                      (supplementary-groups '())
-                      (log-port (current-error-port)))
-  "Modify user account NAME to have all the given settings."
-  ;; Use 'usermod' from the Shadow package.
-  (let ((args `(,@(if uid `("-u" ,(number->string uid)) '())
-                "-g" ,(if (number? group) (number->string group) group)
-                ,@(if (pair? supplementary-groups)
-                      `("-G" ,(string-join supplementary-groups ","))
-                      '())
-                ,@(if comment `("-c" ,comment) '())
-                ;; Don't use '--move-home'.
-                ,@(if home `("-d" ,home) '())
-                ,@(if shell `("-s" ,shell) '())
-                ,name)))
-    (zero? (apply system* "usermod" args))))
-
-(define* (delete-user name #:key (log-port (current-error-port)))
-  "Remove user account NAME.  Return #t on success.  This may fail if NAME is
-logged in."
-  (format log-port "deleting user '~a'...~%" name)
-  (zero? (system* "userdel" name)))
-
-(define* (delete-group name #:key (log-port (current-error-port)))
-  "Remove group NAME.  Return #t on success."
-  (format log-port "deleting group '~a'...~%" name)
-  (zero? (system* "groupdel" name)))
-
-(define* (ensure-user name group
-                      #:key uid comment home create-home?
-                      shell password system?
-                      (supplementary-groups '())
-                      (log-port (current-error-port))
-                      #:rest rest)
-  "Make sure user NAME exists and has the relevant settings."
-  (if (false-if-exception (getpwnam name))
-      (apply modify-user name group rest)
-      (apply add-user name group rest)))
-
 (define (activate-users+groups users groups)
   "Make sure USERS (a list of user account records) and GROUPS (a list of user
 group records) are all available."
-  (define (touch file)
-    (close-port (open-file file "a0b")))
-
-  (define activate-user
-    (lambda (user)
-      (let ((name         (user-account-name user))
-            (uid          (user-account-uid user))
-            (group        (user-account-group user))
-            (supplementary-groups
-             (user-account-supplementary-groups user))
-            (comment      (user-account-comment user))
-            (home         (user-account-home-directory user))
-            (create-home? (user-account-create-home-directory? user))
-            (shell        (user-account-shell user))
-            (password     (user-account-password user))
-            (system?      (user-account-system? user)))
-        (let ((profile-dir (string-append "/var/guix/profiles/per-user/"
-                                          name)))
-          (ensure-user name group
-                       #:uid uid
-                       #:system? system?
-                       #:supplementary-groups supplementary-groups
-                       #:comment comment
-                       #:home home
-                       #:create-home? create-home?
-
-                       #:shell shell
-                       #:password password)
-
-          (unless system?
-            ;; Create the profile directory for the new account.
-            (let ((pw (getpwnam name)))
-              (mkdir-p profile-dir)
-              (chown profile-dir (passwd:uid pw) (passwd:gid pw))))))))
-
-  ;; 'groupadd' aborts if the file doesn't already exist.
-  (touch "/etc/group")
+  (define (make-home-directory user)
+    (let ((home (user-account-home-directory user))
+          (pwd  (getpwnam (user-account-name user))))
+      (mkdir-p home)
+      (chown home (passwd:uid pwd) (passwd:gid pwd))
+      (chmod home #o700)))
 
   ;; Allow home directories to be created under /var/lib.
   (mkdir-p "/var/lib")
 
-  ;; Create the root account so we can use 'useradd' and 'groupadd'.
-  (activate-user (find (compose zero? user-account-uid) users))
+  (let-values (((groups passwd shadow)
+                (user+group-databases users groups)))
+    (write-group groups)
+    (write-passwd passwd)
+    (write-shadow shadow)
 
-  ;; Then create the groups.
-  (for-each (lambda (group)
-              (let ((name     (user-group-name group))
-                    (password (user-group-password group))
-                    (gid      (user-group-id group))
-                    (system?  (user-group-system? group)))
-                (unless (false-if-exception (getgrnam name))
-                  (add-group name
-                             #:gid gid #:password password
-                             #:system? system?))))
-            groups)
-
-  ;; Create the other user accounts.
-  (for-each activate-user users)
-
-  ;; Finally, delete extra user accounts and groups.
-  (for-each delete-user
-            (lset-difference string=?
-                             (map passwd:name (current-users))
-                             (map user-account-name users)))
-  (for-each delete-group
-            (lset-difference string=?
-                             (map group:name (current-groups))
-                             (map user-group-name groups))))
+    ;; Home directories of non-system accounts are created by
+    ;; 'activate-user-home'.
+    (for-each make-home-directory
+              (filter (lambda (user)
+                        (and (user-account-system? user)
+                             (user-account-create-home-directory? user)))
+                      users))))
 
 (define (activate-user-home users)
   "Create and populate the home directory of USERS, a list of tuples, unless
diff --git a/gnu/build/install.scm b/gnu/build/install.scm
index c9ebe124fe..c0d4d44091 100644
--- a/gnu/build/install.scm
+++ b/gnu/build/install.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2013, 2014, 2015, 2016, 2017, 2018, 2019 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2016 Chris Marusich <cmmarusich@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -117,7 +117,6 @@ STORE."
     (directory "/var/tmp" 0 0 #o1777)
     (directory "/var/lock" 0 0 #o1777)
 
-    (directory "/root" 0 0)                       ; an exception
     (directory "/home" 0 0)))
 
 (define (populate-root-file-system system target)
diff --git a/gnu/system/shadow.scm b/gnu/system/shadow.scm
index 4e5b6ae5f2..7dc36f4a45 100644
--- a/gnu/system/shadow.scm
+++ b/gnu/system/shadow.scm
@@ -302,8 +302,6 @@ group."
     #~(begin
         (use-modules (gnu system accounts))
 
-        (setenv "PATH"
-                (string-append #$(@ (gnu packages admin) shadow) "/sbin"))
         (activate-users+groups (map sexp->user-account (list #$@user-specs))
                                (map sexp->user-group (list #$@group-specs))))))
 
