diff --git a/modules/beefy/Cargo.toml b/modules/beefy/Cargo.toml
index d0e5204dcbe..2c552430c98 100644
--- a/modules/beefy/Cargo.toml
+++ b/modules/beefy/Cargo.toml
@@ -32,7 +32,7 @@ sp-std = { git = "https://github.com/paritytech/polkadot-sdk", branch = "master"
 
 [dev-dependencies]
 sp-consensus-beefy = { git = "https://github.com/paritytech/polkadot-sdk", branch = "master" }
-mmr-lib = { package = "ckb-merkle-mountain-range", version = "0.3.2" }
+mmr-lib = { package = "ckb-merkle-mountain-range", version = "0.5.2" }
 pallet-beefy-mmr = { git = "https://github.com/paritytech/polkadot-sdk", branch = "master" }
 pallet-mmr = { git = "https://github.com/paritytech/polkadot-sdk", branch = "master" }
 rand = "0.8.5"
diff --git a/modules/beefy/src/mock_chain.rs b/modules/beefy/src/mock_chain.rs
index c4fa74915bf..c83907f8395 100644
--- a/modules/beefy/src/mock_chain.rs
+++ b/modules/beefy/src/mock_chain.rs
@@ -290,10 +290,10 @@ pub struct BridgedMmrHashMerge;
 impl mmr_lib::Merge for BridgedMmrHashMerge {
 	type Item = TestBridgedMmrNode;
 
-	fn merge(left: &Self::Item, right: &Self::Item) -> Self::Item {
+	fn merge(left: &Self::Item, right: &Self::Item) -> mmr_lib::Result<Self::Item> {
 		let mut concat = left.hash().as_ref().to_vec();
 		concat.extend_from_slice(right.hash().as_ref());
 
-		TestBridgedMmrNode::Hash(TestBridgedMmrHashing::hash(&concat))
+		Ok(TestBridgedMmrNode::Hash(TestBridgedMmrHashing::hash(&concat)))
 	}
 }