diff --git a/core/src/rpc_error.rs b/core/src/rpc_error.rs
index 9125b65c7f..e452c2d985 100644
--- a/core/src/rpc_error.rs
+++ b/core/src/rpc_error.rs
@@ -3,6 +3,7 @@ use solana_sdk::clock::Slot;
 
 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 {
     BlockCleanedUp {
@@ -12,6 +13,7 @@ pub enum RpcCustomError {
     SendTransactionPreflightFailure {
         message: String,
     },
+    SendTransactionIsNotSigned,
 }
 
 impl From<RpcCustomError> for Error {
@@ -33,6 +35,11 @@ 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,
+            },
         }
     }
 }