diff --git a/install/nginxproxymanager-install.sh b/install/nginxproxymanager-install.sh
index 16b7ac5fe..4b36e7f1e 100644
--- a/install/nginxproxymanager-install.sh
+++ b/install/nginxproxymanager-install.sh
@@ -42,7 +42,7 @@ VERSION="$(awk -F'=' '/^VERSION_CODENAME=/{ print $NF }' /etc/os-release)"
 
 msg_info "Installing Openresty"
 curl -fsSL "https://openresty.org/package/pubkey.gpg" | gpg --dearmor -o /etc/apt/trusted.gpg.d/openresty-archive-keyring.gpg
-codename=`grep -Po 'VERSION="[0-9]+ \(\K[^)]+' /etc/os-r
+codename=`grep -Po 'VERSION="[0-9]+ \(\K[^)]+' /etc/os-release`
 echo -e "deb http://openresty.org/package/debian $codename openresty" >/etc/apt/sources.list.d/openresty.list
 $STD apt-get update
 $STD apt-get -y install openresty