diff --git a/lib/irc.js b/lib/irc.js
index 5ee4a9c..65f9949 100644
--- a/lib/irc.js
+++ b/lib/irc.js
@@ -218,7 +218,7 @@ export function formatMessage(msg) {
 		s += " " + msg.params.slice(0, -1).join(" ");
 
 		let last = String(msg.params[msg.params.length - 1]);
-		if (last.length === 0 || last === ":" || last.indexOf(" ") >= 0) {
+		if (last.length === 0 || last.startsWith(":") || last.indexOf(" ") >= 0) {
 			s += " :" + last;
 		} else {
 			s += " " + last;