diff --git a/beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs b/beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs
index 15c863a7dd..09621268ca 100644
--- a/beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs
+++ b/beacon_node/beacon_chain/test_harness/src/beacon_chain_harness.rs
@@ -211,7 +211,7 @@ impl BeaconChainHarness {
         // Produce a new block.
         let block = self.produce_block();
         debug!("Submitting block for processing...");
-        &mut (self.beacon_chain).process_block(block).unwrap();
+        self.beacon_chain.process_block(block).unwrap();
         debug!("...block processed by BeaconChain.");
 
         debug!("Producing free attestations...");