diff --git a/zebra-state/src/service/non_finalized_state/chain.rs b/zebra-state/src/service/non_finalized_state/chain.rs
index b6ab4d4f4ad..b7d5f437c2b 100644
--- a/zebra-state/src/service/non_finalized_state/chain.rs
+++ b/zebra-state/src/service/non_finalized_state/chain.rs
@@ -758,3 +758,14 @@ impl PartialEq for Chain {
 }
 
 impl Eq for Chain {}
+
+impl Default for Chain {
+    fn default() -> Self {
+        Self::new(
+            // TODO: decide if we want to default to None or empty tree
+            Some(Default::default()),
+            Some(Default::default()),
+            Some(Default::default()),
+        )
+    }
+}
diff --git a/zebra-state/src/service/non_finalized_state/tests/prop.rs b/zebra-state/src/service/non_finalized_state/tests/prop.rs
index e1aad540606..f6860f1df96 100644
--- a/zebra-state/src/service/non_finalized_state/tests/prop.rs
+++ b/zebra-state/src/service/non_finalized_state/tests/prop.rs
@@ -39,7 +39,7 @@ fn forked_equals_pushed() -> Result<()> {
             }
 
             // TODO: pass correct trees
-            let forked = full_chain.fork(fork_tip_hash, None, None, None).expect("fork works").expect("hash is present");
+            let forked = full_chain.fork(fork_tip_hash, Some(Default::default()), Some(Default::default()), Some(Default::default())).expect("fork works").expect("hash is present");
 
             // the first check is redundant, but it's useful for debugging
             prop_assert_eq!(forked.blocks.len(), partial_chain.blocks.len());