diff --git a/p2p/src/msg.rs b/p2p/src/msg.rs
index d3f948f13..0a17d70cb 100644
--- a/p2p/src/msg.rs
+++ b/p2p/src/msg.rs
@@ -31,8 +31,8 @@ use types::*;
 /// Current latest version of the protocol
 pub const PROTOCOL_VERSION: u32 = 1;
 
-/// Grin's user agent with current version (TODO externalize)
-pub const USER_AGENT: &'static str = "MW/Grin 0.1";
+/// Grin's user agent with current version
+pub const USER_AGENT: &'static str = concat!("MW/Grin ", env!("CARGO_PKG_VERSION"));
 
 /// Magic number expected in the header of every message
 const MAGIC: [u8; 2] = [0x1e, 0xc5];
diff --git a/p2p/tests/peer_handshake.rs b/p2p/tests/peer_handshake.rs
index 4e81cad3b..90be2f1c1 100644
--- a/p2p/tests/peer_handshake.rs
+++ b/p2p/tests/peer_handshake.rs
@@ -76,6 +76,8 @@ fn peer_handshake() {
 		net_adapter,
 	).unwrap();
 
+	assert!(peer.info.user_agent.ends_with(env!("CARGO_PKG_VERSION")));
+
 	peer.start(socket);
 	thread::sleep(time::Duration::from_secs(1));