diff --git a/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-install b/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-install
index 980d1e5..832a4db 100644
--- a/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-install
+++ b/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-install
@@ -1,12 +1,9 @@
 #!/bin/sh
 set -eu
 
-# Are we running systemd?
+# Enable and start systemd services
 if which systemctl >/dev/null 2>&1 && systemctl is-system-running | grep -vq offline >/dev/null 2>&1; then
-    # Does `mullvad-daemon.service` exist?
-    if systemctl list-unit-files mullvad-daemon.service >/dev/null 2>&1; then
-      systemctl enable "/usr/lib/systemd/system/mullvad-daemon.service"
-      systemctl start mullvad-daemon.service || echo "Failed to start mullvad-daemon.service"
-      systemctl enable "/usr/lib/systemd/system/mullvad-early-boot-blocking.service"
-    fi
+  systemctl enable "/usr/lib/systemd/system/mullvad-daemon.service"
+  systemctl start mullvad-daemon.service || echo "Failed to start mullvad-daemon.service"
+  systemctl enable "/usr/lib/systemd/system/mullvad-early-boot-blocking.service"
 fi
diff --git a/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-upgrade b/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-upgrade
index 980d1e5..832a4db 100644
--- a/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-upgrade
+++ b/mullvad-vpn-daemon/mullvad-vpn-daemon-systemd.post-upgrade
@@ -1,12 +1,9 @@
 #!/bin/sh
 set -eu
 
-# Are we running systemd?
+# Enable and start systemd services
 if which systemctl >/dev/null 2>&1 && systemctl is-system-running | grep -vq offline >/dev/null 2>&1; then
-    # Does `mullvad-daemon.service` exist?
-    if systemctl list-unit-files mullvad-daemon.service >/dev/null 2>&1; then
-      systemctl enable "/usr/lib/systemd/system/mullvad-daemon.service"
-      systemctl start mullvad-daemon.service || echo "Failed to start mullvad-daemon.service"
-      systemctl enable "/usr/lib/systemd/system/mullvad-early-boot-blocking.service"
-    fi
+  systemctl enable "/usr/lib/systemd/system/mullvad-daemon.service"
+  systemctl start mullvad-daemon.service || echo "Failed to start mullvad-daemon.service"
+  systemctl enable "/usr/lib/systemd/system/mullvad-early-boot-blocking.service"
 fi
diff --git a/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-deinstall b/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-deinstall
index 10004b3..574a7dd 100644
--- a/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-deinstall
+++ b/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-deinstall
@@ -1,5 +1,6 @@
 #!/bin/sh
 set -eu
 
+# Log out and remove any firewall rules
 mullvad-setup reset-firewall || echo "Failed to reset firewall"
 mullvad-setup remove-device || echo "Failed to remove device from account"
diff --git a/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-upgrade b/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-upgrade
index 9f88962..aa89b4b 100644
--- a/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-upgrade
+++ b/mullvad-vpn-daemon/mullvad-vpn-daemon.pre-upgrade
@@ -1,9 +1,9 @@
 #!/bin/sh
 set -eu
 
-# Are we running systemd?
+# Stop the daemon gracefully, and set up firewall rules to prevent network
+# leaks during upgrade.
 if which systemctl >/dev/null 2>&1 && systemctl is-system-running | grep -vq offline >/dev/null 2>&1; then
-    # Is `mullvad-daemon.service` running?
     if systemctl status mullvad-daemon >/dev/null 2>&1; then
         mullvad-setup prepare-restart || true
         systemctl stop mullvad-daemon.service
@@ -14,5 +14,5 @@ if which systemctl >/dev/null 2>&1 && systemctl is-system-running | grep -vq off
     fi
 fi
 
-# Since we are upgrading mullvad-daemon, it will probably have current IP baked into itself.
+# Clear the cached API IP address.
 rm -f /var/cache/mullvad-vpn/api-ip-address.txt