diff --git a/debian/postinst b/debian/postinst
index d3a36f4ed..4683d31f0 100755
--- a/debian/postinst
+++ b/debian/postinst
@@ -12,7 +12,7 @@ daemongroup=plinth
 # invocations. This leads to plinth not being able to run root privileges. This
 # is because of our own restrictions in /etc/security/access.conf. Since Plinth
 # is locked out after upgrade, we need to do this in postinst.
-sed -ie 's+-:ALL EXCEPT root fbx (admin) (sudo):ALL+-:ALL EXCEPT root fbx plinth (admin) (sudo):ALL+' /etc/security/access.conf
+sed -i 's+-:ALL EXCEPT root fbx (admin) (sudo):ALL+-:ALL EXCEPT root fbx plinth (admin) (sudo):ALL+' /etc/security/access.conf
 
 case "$1" in
     configure)