diff --git a/install/prometheus-install.sh b/install/prometheus-install.sh
index 0cbcbea07..4893e6dc3 100644
--- a/install/prometheus-install.sh
+++ b/install/prometheus-install.sh
@@ -36,7 +36,7 @@ ExecStart=/usr/local/bin/prometheus \
     --config.file=/etc/prometheus/prometheus.yml \
     --storage.tsdb.path=/var/lib/prometheus/ \
     --web.listen-address=0.0.0.0:9090
-ExecReload=/bin/kill -HUP \$MAINPID
+ExecReload=/bin/kill -HUP $MAINPID
 
 [Install]
 WantedBy=multi-user.target