diff --git a/chains/nomad-substrate/CHANGELOG.md b/chains/nomad-substrate/CHANGELOG.md
index 8de06b5e..56a28f47 100644
--- a/chains/nomad-substrate/CHANGELOG.md
+++ b/chains/nomad-substrate/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 ### Unreleased
 
+- Change `double_update` to a NOP
 - Update `update` method with new max index field
 - `produce_update` checks that tree has at least 1 element (bug fix)
 - Add timelag functionality to `NomadOnlineClient` which wraps storage fetches with timelagged fetches
diff --git a/chains/nomad-substrate/src/home.rs b/chains/nomad-substrate/src/home.rs
index b47a382c..00cc2310 100644
--- a/chains/nomad-substrate/src/home.rs
+++ b/chains/nomad-substrate/src/home.rs
@@ -267,7 +267,9 @@ where
 
     #[tracing::instrument(err, skip(self))]
     async fn double_update(&self, _double: &DoubleUpdate) -> Result<TxOutcome, Self::Error> {
-        unimplemented!("Double update deprecated for Substrate implementations")
+        Ok(TxOutcome {
+            txid: Default::default(),
+        })
     }
 }