diff --git a/bitcoin/src/sign_message.rs b/bitcoin/src/sign_message.rs
index 094b66aef..0b3030de5 100644
--- a/bitcoin/src/sign_message.rs
+++ b/bitcoin/src/sign_message.rs
@@ -101,11 +101,7 @@ mod message_signing {
         pub fn serialize(&self) -> [u8; 65] {
             let (recid, raw) = self.signature.serialize_compact();
             let mut serialized = [0u8; 65];
-            serialized[0] = 27;
-            serialized[0] += recid.to_i32() as u8;
-            if self.compressed {
-                serialized[0] += 4;
-            }
+            serialized[0] = recid.to_i32() as u8 + if self.compressed { 31 } else { 27 };
             serialized[1..].copy_from_slice(&raw[..]);
             serialized
         }