diff --git a/systemd/bip.service b/systemd/bip.service
index 827e134..5709430 100644
--- a/systemd/bip.service
+++ b/systemd/bip.service
@@ -11,7 +11,7 @@ EnvironmentFile=/run/sysconfig/bip
 Type=forking
 User=bip
 Group=bip
-ExecStartPre=/bin/sh -c '[ $ENABLED != 0 ]'
+ExecStartPre=/bin/sh -c '[ ${ENABLED:-1} != 0 ]'
 ExecStart=/usr/bin/bip $DAEMON_ARGS
 ExecReload=/bin/kill -HUP $MAINPID
 RuntimeDirectory=bip