diff --git a/core/src/rpc_error.rs b/core/src/rpc_error.rs
index 276ad96c5f..a1ed091aad 100644
--- a/core/src/rpc_error.rs
+++ b/core/src/rpc_error.rs
@@ -4,6 +4,7 @@ use solana_sdk::clock::Slot;
 const JSON_RPC_SERVER_ERROR_0: i64 = -32000;
 const JSON_RPC_SERVER_ERROR_1: i64 = -32001;
 const JSON_RPC_SERVER_ERROR_2: i64 = -32002;
+const JSON_RPC_SERVER_ERROR_3: i64 = -32003;
 
 pub enum RpcCustomError {
     NonexistentClusterRoot {
@@ -17,6 +18,7 @@ pub enum RpcCustomError {
     SendTransactionPreflightFailure {
         message: String,
     },
+    SendTransactionIsNotSigned,
 }
 
 impl From<RpcCustomError> for Error {
@@ -49,6 +51,11 @@ impl From<RpcCustomError> for Error {
                 message,
                 data: None,
             },
+            RpcCustomError::SendTransactionIsNotSigned => Self {
+                code: ErrorCode::ServerError(JSON_RPC_SERVER_ERROR_3),
+                message: "Transaction is not signed".to_string(),
+                data: None,
+            },
         }
     }
 }