diff --git a/configuration/system-configuration.sh b/configuration/system-configuration.sh
index fa2e7def257..0020053edf7 100644
--- a/configuration/system-configuration.sh
+++ b/configuration/system-configuration.sh
@@ -26,6 +26,7 @@ if test -n "$grubDevice"; then
         $grub/sbin/grub-install "$grubDevice" --no-floppy --recheck
     fi
 fi
+sync
 EOF
 
 chmod +x $out/bin/switch-to-configuration
diff --git a/helpers/accounts.sh b/helpers/accounts.sh
new file mode 100644
index 00000000000..1e189c56e7f
--- /dev/null
+++ b/helpers/accounts.sh
@@ -0,0 +1,20 @@
+userExists() {
+    local name="$1"
+    if id -u "$name" > /dev/null 2>&1; then
+        return 0 # true
+    else
+        return 1 # false
+    fi
+}
+
+
+createUser() {
+    local name="$1"
+    local password="$2"
+    local uid="$3"
+    local gid="$4"
+    local gecos="$5"
+    local homedir="$6"
+    local shell="$7"
+    echo "$name:$password:$uid:$gid:$gecos:$homedir:$shell" >> /etc/passwd
+}
diff --git a/upstart-jobs/sshd.nix b/upstart-jobs/sshd.nix
index 466c7616f55..3f210467277 100644
--- a/upstart-jobs/sshd.nix
+++ b/upstart-jobs/sshd.nix
@@ -10,6 +10,8 @@ start on network-interfaces/started
 stop on network-interfaces/stop
 
 start script
+    source ${../helpers/accounts.sh}
+
     mkdir -m 0555 -p /var/empty
 
     mkdir -m 0755 -p /etc/ssh
@@ -20,8 +22,8 @@ start script
         ${openssh}/bin/ssh-keygen -t dsa -b 1024 -f /etc/ssh/ssh_host_dsa_key -N ''
     fi
 
-    if ! grep -q '^sshd:' /etc/passwd; then
-        echo 'sshd:x:74:74:SSH privilege separation user:/var/empty:/noshell' >> /etc/passwd
+    if ! userExists sshd; then
+        createUser sshd x 74 74 'SSH privilege separation user' /var/empty /noshell
     fi
 
 end script