diff --git a/pkgs/at-exp-lib/at-exp/lang/reader.rkt b/pkgs/at-exp-lib/at-exp/lang/reader.rkt
index 14285738e7..7fbb71698e 100644
--- a/pkgs/at-exp-lib/at-exp/lang/reader.rkt
+++ b/pkgs/at-exp-lib/at-exp/lang/reader.rkt
@@ -44,7 +44,6 @@
             (try-dynamic-require 'syntax-color/scribble-lexer 'scribble-lexer)]
            [(definitions-text-surrogate)
             'scribble/private/indentation]
-           [(drracket:default-extension) "scrbl"]
            [(drracket:indentation)
             (dynamic-require 'scribble/private/indentation 'determine-spaces)]
            [else (fallback)]))))))