diff --git a/profile b/profile
index ad2174e..38b7bf8 100755
--- a/profile
+++ b/profile
@@ -88,7 +88,7 @@ then
     TERM=screen-256color
 fi
 
-if test '!' -v USER -a -v USERNAME
+if test -z "$USER" -a -n "$USERNAME"
 then
     export USER=$USERNAME
 fi