diff --git a/substrate/tendermint/machine/README.md b/substrate/tendermint/machine/README.md
index ac497bb9..fe05a4c6 100644
--- a/substrate/tendermint/machine/README.md
+++ b/substrate/tendermint/machine/README.md
@@ -14,9 +14,8 @@ implementation of the [academic protocol](https://arxiv.org/pdf/1807.04938.pdf).
   being under Serai, which uses Substrate, which uses SCALE. Accordingly, when
   deciding which of the three (mutually incompatible) options to support...
 
-- tokio is explicitly used for the asynchronous task which runs the Tendermint
-  machine. Ideally, `futures-rs` would be used enabling any async runtime to be
-  used.
+- The only supported runtime is tokio due to requiring a `sleep` implementation.
+  Ideally, the runtime choice will be moved to a feature in the future.
 
 - It is possible for `add_block` to be called on a block which failed (or never
   went through in the first place) validation. This is a break from the paper