diff --git a/zebra-rpc/src/config.rs b/zebra-rpc/src/config.rs
index f2adb66d10f..2a91d14334b 100644
--- a/zebra-rpc/src/config.rs
+++ b/zebra-rpc/src/config.rs
@@ -54,6 +54,8 @@ pub struct Config {
     /// We keep it just for backward compatibility but it actually do nothing.
     /// It was something configurable when the RPC server was based in the jsonrpc-core crate,
     /// not anymore since we migrated to jsonrpsee.
+    // TODO: Prefix this field name with an underscore so it's clear that it's now unused, and
+    //       use serde(rename) to continue successfully deserializing old configs.
     pub parallel_cpu_threads: usize,
 
     /// Test-only option that makes Zebra say it is at the chain tip,
diff --git a/zebra-rpc/src/methods.rs b/zebra-rpc/src/methods.rs
index 66c9bd32f11..8634ec43ef5 100644
--- a/zebra-rpc/src/methods.rs
+++ b/zebra-rpc/src/methods.rs
@@ -1436,7 +1436,7 @@ where
             match nix::sys::signal::raise(nix::sys::signal::SIGINT) {
                 Ok(_) => Ok("Zebra server stopping".to_string()),
                 Err(error) => Err(ErrorObject::owned(
-                    ErrorCode::ServerError(ErrorCode::InternalError.code()).code(),
+                    ErrorCode::InternalError.code(),
                     format!("Failed to shut down: {}", error).as_str(),
                     None::<()>,
                 )),
diff --git a/zebra-rpc/src/methods/get_block_template_rpcs/get_block_template.rs b/zebra-rpc/src/methods/get_block_template_rpcs/get_block_template.rs
index c6fe975a0c7..baa0200db1f 100644
--- a/zebra-rpc/src/methods/get_block_template_rpcs/get_block_template.rs
+++ b/zebra-rpc/src/methods/get_block_template_rpcs/get_block_template.rs
@@ -130,13 +130,7 @@ where
     let block_verifier_router_response = block_verifier_router
         .ready()
         .await
-        .map_err(|error| {
-            ErrorObject::owned(
-                ErrorCode::ServerError(0).code(),
-                error.to_string(),
-                None::<()>,
-            )
-        })?
+        .map_err(|error| ErrorObject::owned(0, error.to_string(), None::<()>))?
         .call(zebra_consensus::Request::CheckProposal(Arc::new(block)))
         .await;
 
@@ -223,13 +217,10 @@ where
         + 'static,
 {
     let request = zebra_state::ReadRequest::ChainInfo;
-    let response = state.oneshot(request.clone()).await.map_err(|error| {
-        ErrorObject::owned(
-            ErrorCode::ServerError(0).code(),
-            error.to_string(),
-            None::<()>,
-        )
-    })?;
+    let response = state
+        .oneshot(request.clone())
+        .await
+        .map_err(|error| ErrorObject::owned(0, error.to_string(), None::<()>))?;
 
     let chain_info = match response {
         zebra_state::ReadResponse::ChainInfo(chain_info) => chain_info,
@@ -259,13 +250,7 @@ where
     let response = mempool
         .oneshot(mempool::Request::FullTransactions)
         .await
-        .map_err(|error| {
-            ErrorObject::owned(
-                ErrorCode::ServerError(0).code(),
-                error.to_string(),
-                None::<()>,
-            )
-        })?;
+        .map_err(|error| ErrorObject::owned(0, error.to_string(), None::<()>))?;
 
     // TODO: Order transactions in block templates based on their dependencies