gistfile1.txt

diff --git a/src/Perl6/Grammar.nqp b/src/Perl6/Grammar.nqp
index e56f887..d996236 100644
--- a/src/Perl6/Grammar.nqp
+++ b/src/Perl6/Grammar.nqp
@@ -3592,7 +3592,10 @@ grammar Perl6::Grammar is HLL::Grammar does STD {
 
         # This also becomes the current MAIN. Also place it in %?LANG.
         %*LANG<MAIN> := self.WHAT;
-        $*W.install_lexical_symbol($*W.cur_lexpad(), '%?LANG', $*W.p6ize_recursive(%*LANG));
+        unless $*W.cur_lexpad.symbol('%?LANG') {
+            $*W.install_lexical_symbol($*W.cur_lexpad(), '%?LANG',
+                $*W.p6ize_recursive(%*LANG));
+        }
         
         # Declarand should get precedence traits.
         if $is_oper && nqp::isconcrete($declarand) {