diff --git a/src/rmc/response.rs b/src/rmc/response.rs
index 30ec03f..cc82b17 100644
--- a/src/rmc/response.rs
+++ b/src/rmc/response.rs
@@ -7,8 +7,7 @@ use crate::prudp::packet::flags::{NEED_ACK, RELIABLE};
 use crate::prudp::packet::PacketOption::FragmentId;
 use crate::prudp::packet::types::DATA;
 use crate::prudp::socket::{ConnectionData, SocketData};
-
-
+use crate::rmc::structures::qresult::ERROR_MASK;
 
 pub enum RMCResponseResult {
     Success{
@@ -67,6 +66,7 @@ pub fn generate_response(protocol_id: u8, response: RMCResponseResult) -> io::Re
         } => {
             data_out.push(0);
             let error_code_val: u32 = error_code.into();
+            let error_code_val = error_code_val | ERROR_MASK;
             data_out.write_all(bytes_of(&error_code_val))?;
             data_out.write_all(bytes_of(&call_id))?;
         }
diff --git a/src/rmc/structures/qresult.rs b/src/rmc/structures/qresult.rs
index 6a16074..d4a5078 100644
--- a/src/rmc/structures/qresult.rs
+++ b/src/rmc/structures/qresult.rs
@@ -5,7 +5,7 @@ use crate::endianness::{IS_BIG_ENDIAN, ReadExtensions};
 use crate::rmc::response::ErrorCode;
 use crate::rmc::structures::{RmcSerialize, Result};
 
-const ERROR_MASK: u32 =  1 << 31;
+pub const ERROR_MASK: u32 =  1 << 31;
 
 #[derive(Pod, Zeroable, Copy, Clone, SwapEndian)]
 #[repr(transparent)]