diff --git a/src/uisupport/uistyle.cpp b/src/uisupport/uistyle.cpp
index d020bb0..c322a48 100644
--- a/src/uisupport/uistyle.cpp
+++ b/src/uisupport/uistyle.cpp
@@ -692,7 +692,7 @@ quint8 UiStyle::StyledMessage::senderHash() const {
   QString nick = nickFromMask(sender()).toLower();
   if(!nick.isEmpty()) {
     int chopCount = 0;
-    while(nick.at(nick.count() - 1 - chopCount) == '_')
+    while((nick.count() - 1 - chopCount >= 0) && (nick.at(nick.count() - 1 - chopCount) == '_'))
       chopCount++;
     if(chopCount < nick.size())
       nick.chop(chopCount);