diff --git a/xCAT-server/lib/xcat/plugins/aixinstall.pm b/xCAT-server/lib/xcat/plugins/aixinstall.pm
index 5edffd07d..722c2fbac 100644
--- a/xCAT-server/lib/xcat/plugins/aixinstall.pm
+++ b/xCAT-server/lib/xcat/plugins/aixinstall.pm
@@ -7659,7 +7659,7 @@ sub prenimnodeset
                 }
 
                 # check the valid attributes.
-                if (grep(/$attr/, @validattr))
+                if (grep(/^$attr$/, @validattr))
                 {
                     $attrs{$attr} = $value;
                 }