diff --git a/yarn-project/foundation/src/json-rpc/server/json_rpc_server.ts b/yarn-project/foundation/src/json-rpc/server/json_rpc_server.ts
index dee461570e6..f217fee70dc 100644
--- a/yarn-project/foundation/src/json-rpc/server/json_rpc_server.ts
+++ b/yarn-project/foundation/src/json-rpc/server/json_rpc_server.ts
@@ -91,7 +91,7 @@ export class JsonRpcServer {
           } catch (err: any) {
             // Propagate the error message to the client. Plenty of the errors are expected to occur (e.g. adding
             // a duplicate recipient) so this is necessary.
-            ctx.status = 409;
+            ctx.status = 400;
             ctx.body = { error: err.message };
           }
         });
@@ -121,7 +121,7 @@ export class JsonRpcServer {
           } catch (err: any) {
             // Propagate the error message to the client. Plenty of the errors are expected to occur (e.g. adding
             // a duplicate recipient) so this is necessary.
-            ctx.status = 409;
+            ctx.status = 400;
             ctx.body = { error: err.message };
           }
         }