diff --git a/src/libsyntax/parse/lexer/mod.rs b/src/libsyntax/parse/lexer/mod.rs
index 9f6aa4d2a78d..1402b7888dd1 100644
--- a/src/libsyntax/parse/lexer/mod.rs
+++ b/src/libsyntax/parse/lexer/mod.rs
@@ -1467,6 +1467,7 @@ impl<'a> StringReader<'a> {
 
     fn peeking_at_comment(&self) -> bool {
         (self.curr_is('/') && self.nextch_is('/')) || (self.curr_is('/') && self.nextch_is('*')) ||
+        // consider shebangs comments, but not inner attributes
         (self.curr_is('#') && self.nextch_is('!') && !self.nextnextch_is('['))
     }