diff --git a/js-assembler/assemble.rkt b/js-assembler/assemble.rkt
index 76fde63..7a30e3f 100644
--- a/js-assembler/assemble.rkt
+++ b/js-assembler/assemble.rkt
@@ -44,6 +44,7 @@
     
     (define-values (basic-blocks entry-points) (fracture stmts))
     
+    (: function-entry-and-exit-names (Setof Symbol))
     (define function-entry-and-exit-names
       (list->set (get-function-entry-and-exit-names stmts)))