diff --git a/ops/README.md b/ops/README.md
index bd234f4236..fcb4262f9a 100644
--- a/ops/README.md
+++ b/ops/README.md
@@ -34,8 +34,8 @@ Cases where code is optimized away:
 The macro will infer and try to auto generate V8 fast API call trait impl for
 `sync` ops with:
 
-- arguments: integers / `&mut OpState`
-- return_type: integers
+- arguments: integers, bool, `&mut OpState`, `&[u8]`, &mut [u8]`, `&[u32]`, `&mut [u32]` 
+- return_type: integers, bool
 
 The `#[op(fast)]` attribute should be used to enforce fast call generation at
 compile time.