diff --git a/ezjail-admin b/ezjail-admin
index 9ab376b..37478f0 100755
--- a/ezjail-admin
+++ b/ezjail-admin
@@ -421,7 +421,7 @@ delete)
   fetchjailinfo $1
 
   # check for existence of jail in our records
-  [ -n "${ezjail_config}" ] || exerr "Error: Nothing known about jail ${ezjail_name}."
+  [ -z "${ezjail_config}" ] || exerr "Error: Nothing known about jail ${ezjail_name}."
 
   # if jail is still running, refuse to go any further
   [ -n "${ezjail_id}" ] && exerr "Error: Jail appears to be still running, stop it first."
@@ -609,7 +609,7 @@ config)
   fetchjailinfo $1
 
   # check for existence of jail in our records
-  [ -n "${ezjail_config}" ] || exerr "Error: Nothing known about jail ${ezjail_name}."
+  [ -z "${ezjail_config}" ] || exerr "Error: Nothing known about jail ${ezjail_name}."
 
   # Nothing to be configured?
   [ -z "${ezjail_setrunnable}" -a -z "${ezjail_new_name}" -a -z "${ezjail_imageaction}" ] && echo "Warning: No config option specified."