diff --git a/server/gameserver/human.cc b/server/gameserver/human.cc
index cfd15232..611736ee 100644
--- a/server/gameserver/human.cc
+++ b/server/gameserver/human.cc
@@ -64,7 +64,7 @@ void PlayerStats::Statement(Human* sender)
                  });
             std::sort
                 (rank_list.begin(), rank_list.end(),
-                 [cmpFunc] (std::vector<Human*>& a, std::vector<Human*>& b )
+                 [cmpFunc] (const std::vector<Human*>& a, const std::vector<Human*>& b )
                  {
                      return cmpFunc(a[0], b[0]) > 0;
                  });