diff --git a/whalesong/parser/parse-bytecode-5.3.rkt b/whalesong/parser/parse-bytecode-5.3.rkt
index 1839d3b..5e55c7b 100644
--- a/whalesong/parser/parse-bytecode-5.3.rkt
+++ b/whalesong/parser/parse-bytecode-5.3.rkt
@@ -6,7 +6,8 @@
 
 
 (version-case
-  [(version<= "5.2.900" (version))
+  [(and (version<= "5.2.900" (version))
+        (version< (version) "5.3.3.7"))
 
    ;; Parsing Racket 5.3 bytecode structures into our own structures.
    (require "path-rewriter.rkt"