diff --git a/scheme/cyclone/cps-opt-local-var-redux.scm b/scheme/cyclone/cps-opt-local-var-redux.scm
index 678ea05e..be573f4d 100644
--- a/scheme/cyclone/cps-opt-local-var-redux.scm
+++ b/scheme/cyclone/cps-opt-local-var-redux.scm
@@ -52,6 +52,7 @@
           (ast:lambda? (car exp))
           (equal? (length exp) 2)
           (ast:lambda? (cadr exp))
+          (list? (ast:lambda-args (cadr exp)))
           (equal? 1 (length (ast:lambda-args (cadr exp))))
           (lvr:local-tail-call-only? 
             (ast:lambda-body (car exp))