diff --git a/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/5.diff b/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/5.diff
index 402c54fc40..5ca0924ba4 100644
--- a/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/5.diff
+++ b/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/5.diff
@@ -8,3 +8,8 @@
 >         (in-hole E v_1)
 238d237
 < 
+270a270,273
+> 
+> (define small-counter-example
+>   (term (tl ((cons 1) nil))))
+> (test-equal (check small-counter-example) #f)
diff --git a/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/stlc-5.rkt b/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/stlc-5.rkt
index 11b2f09e18..249d479082 100644
--- a/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/stlc-5.rkt
+++ b/pkgs/redex-pkgs/redex-examples/redex/examples/benchmark/stlc/stlc-5.rkt
@@ -267,3 +267,7 @@
       (begin0
         (generate-term stlc M #:i-th index)
         (set! index (add1 index))))))
+
+(define small-counter-example
+  (term (tl ((cons 1) nil))))
+(test-equal (check small-counter-example) #f)