diff --git a/collects/typed-scheme/private/infer-unit.ss b/collects/typed-scheme/private/infer-unit.ss
index 24f536ed48..8d197b94e0 100644
--- a/collects/typed-scheme/private/infer-unit.ss
+++ b/collects/typed-scheme/private/infer-unit.ss
@@ -105,7 +105,7 @@
     [(_ _) (fail! t s)]))
 
 (define (cgen/eff/list V X ts ss)
-  (unless (= (length ts) (length ss)) (fail! ts ss))
+  (unless (>= (length ts) (length ss)) (fail! ts ss))
   (cset-meet* (for/list ([t ts] [s ss]) (cgen/eff V X t s))))
 
 (define (cgen/arr V X t-arr s-arr)