diff --git a/src/Libraries/Base1/Prelude.bs b/src/Libraries/Base1/Prelude.bs
index 4a2b65ba5..8b73457cd 100644
--- a/src/Libraries/Base1/Prelude.bs
+++ b/src/Libraries/Base1/Prelude.bs
@@ -3572,7 +3572,7 @@ instance (TupleSize' a n) => TupleSize a n where {}
 
 class TupleSize' a n | a -> n where {}
 instance TupleSize' a 1 where {}
-instance (TupleSize' b (TSub n 1)) => TupleSize' (a, b) n where {}
+instance (TupleSize' b n) => TupleSize' (a, b) (TAdd n 1) where {}
 
 -- FUNCTIONS TO REPLACE UNAVAILABLE INFIXES