diff --git a/firewood/src/db.rs b/firewood/src/db.rs
index 09a0285eb..37585fb41 100644
--- a/firewood/src/db.rs
+++ b/firewood/src/db.rs
@@ -305,12 +305,12 @@ impl<S: ShaleStore<Node> + Send + Sync> api::DbView for DbRev<S> {
             .map_err(|e| api::Error::IO(std::io::Error::new(ErrorKind::Other, e)))
     }
 
-    async fn range_proof<K: api::KeyType, V, N>(
+    async fn range_proof<K: api::KeyType, V>(
         &self,
         _first_key: Option<K>,
         _last_key: Option<K>,
-        _limit: usize,
-    ) -> Result<Option<api::RangeProof<K, V, N>>, api::Error> {
+        _limit: Option<usize>,
+    ) -> Result<Option<api::RangeProof<Vec<u8>, Vec<u8>>>, api::Error> {
         todo!()
     }
 }
diff --git a/firewood/src/db/proposal.rs b/firewood/src/db/proposal.rs
index bfe6caa7e..8afd099ec 100644
--- a/firewood/src/db/proposal.rs
+++ b/firewood/src/db/proposal.rs
@@ -295,12 +295,12 @@ impl api::DbView for Proposal {
             .map_err(|e| api::Error::IO(std::io::Error::new(ErrorKind::Other, e)))
     }
 
-    async fn range_proof<K, V, N>(
+    async fn range_proof<K, V>(
         &self,
         _first_key: Option<K>,
         _last_key: Option<K>,
-        _limit: usize,
-    ) -> Result<Option<api::RangeProof<K, V, N>>, api::Error>
+        _limit: Option<usize>,
+    ) -> Result<Option<api::RangeProof<Vec<u8>, Vec<u8>>>, api::Error>
     where
         K: api::KeyType,
     {
diff --git a/firewood/src/v2/api.rs b/firewood/src/v2/api.rs
index 0ddacbe71..9272576e8 100644
--- a/firewood/src/v2/api.rs
+++ b/firewood/src/v2/api.rs
@@ -71,15 +71,18 @@ pub enum Error {
     InvalidProposal,
 
     #[error("Internal error")]
-    InternalError(Box<dyn std::error::Error>),
+    InternalError(Box<dyn std::error::Error + Send>),
+
+    #[error("RangeProofError")]
+    RangeProofError(String),
 }
 
 /// A range proof, consisting of a proof of the first key and the last key,
 /// and a vector of all key/value pairs
 #[derive(Debug)]
-pub struct RangeProof<K, V, N> {
-    pub first_key: Proof<N>,
-    pub last_key: Proof<N>,
+pub struct RangeProof<K, V> {
+    pub first_key: Proof<Vec<u8>>,
+    pub last_key: Proof<Vec<u8>>,
     pub middle: Vec<(K, V)>,
 }
 
@@ -152,12 +155,12 @@ pub trait DbView {
     /// * `last_key` - If None, continue to the end of the database
     /// * `limit` - The maximum number of keys in the range proof
     ///
-    async fn range_proof<K: KeyType, V, N>(
+    async fn range_proof<K: KeyType, V: Send + Sync>(
         &self,
         first_key: Option<K>,
         last_key: Option<K>,
-        limit: usize,
-    ) -> Result<Option<RangeProof<K, V, N>>, Error>;
+        limit: Option<usize>,
+    ) -> Result<Option<RangeProof<Vec<u8>, Vec<u8>>>, Error>;
 }
 
 /// A proposal for a new revision of the database.
diff --git a/firewood/src/v2/emptydb.rs b/firewood/src/v2/emptydb.rs
index 762504aad..746373ab1 100644
--- a/firewood/src/v2/emptydb.rs
+++ b/firewood/src/v2/emptydb.rs
@@ -66,12 +66,12 @@ impl DbView for HistoricalImpl {
         Ok(None)
     }
 
-    async fn range_proof<K: KeyType, V, N>(
+    async fn range_proof<K: KeyType, V>(
         &self,
         _first_key: Option<K>,
         _last_key: Option<K>,
-        _limit: usize,
-    ) -> Result<Option<RangeProof<K, V, N>>, Error> {
+        _limit: Option<usize>,
+    ) -> Result<Option<RangeProof<Vec<u8>, Vec<u8>>>, Error> {
         Ok(None)
     }
 }
diff --git a/firewood/src/v2/propose.rs b/firewood/src/v2/propose.rs
index d00e8ee2a..053a6a059 100644
--- a/firewood/src/v2/propose.rs
+++ b/firewood/src/v2/propose.rs
@@ -128,12 +128,12 @@ impl<T: api::DbView + Send + Sync> api::DbView for Proposal<T> {
         todo!()
     }
 
-    async fn range_proof<KT: KeyType, VT, NT>(
+    async fn range_proof<KT: KeyType, VT>(
         &self,
         _first_key: Option<KT>,
         _last_key: Option<KT>,
-        _limit: usize,
-    ) -> Result<Option<api::RangeProof<KT, VT, NT>>, api::Error> {
+        _limit: Option<usize>,
+    ) -> Result<Option<api::RangeProof<Vec<u8>, Vec<u8>>>, api::Error> {
         todo!()
     }
 }