diff --git a/src/messages/messagebuilder.cpp b/src/messages/messagebuilder.cpp
index 56dc86cf2..9a6ff88eb 100644
--- a/src/messages/messagebuilder.cpp
+++ b/src/messages/messagebuilder.cpp
@@ -65,7 +65,7 @@ QString MessageBuilder::matchLink(const QString &string)
     "(?:\\.(?:[1-9]\\d?|1\\d\\d|2[0-4]\\d|25[0-4]))"
     "|"
     // host name
-    "(?:(?:[a-z\\x{00a1}-\\x{ffff}0-9]-*)*[a-z\\x{00a1}-\\x{ffff}0-9]+)"
+    "(?:(?:[_a-z\\x{00a1}-\\x{ffff}0-9]-*)*[a-z\\x{00a1}-\\x{ffff}0-9]+)"
     // domain name
     "(?:\\.(?:[a-z\\x{00a1}-\\x{ffff}0-9]-*)*[a-z\\x{00a1}-\\x{ffff}0-9]+)*"
     // TLD identifier