diff --git a/lib/irc.js b/lib/irc.js
index e4352cb..82359a1 100644
--- a/lib/irc.js
+++ b/lib/irc.js
@@ -258,7 +258,7 @@ export function parseTargetPrefix(s, allowedPrefixes = STD_MEMBERSHIPS) {
 
 const alphaNum = (() => {
 	try {
-		return new RegExp(/^\p{L}$/, "u");
+		return new RegExp(/^[\p{L}0-9]$/, "u");
 	} catch (e) {
 		return new RegExp(/^[a-zA-Z0-9]$/, "u");
 	}