diff --git a/server/gameserver/bullet.cc b/server/gameserver/bullet.cc
index b18ec541..b925803a 100644
--- a/server/gameserver/bullet.cc
+++ b/server/gameserver/bullet.cc
@@ -398,7 +398,7 @@ void Bullet::MapServiceUpdate()
             }
             move_length -= step_len;
             GetMutablePos().AddGlmVec3(dir * step_len);
-            float distance = GetPos().Distance2D2(born_pos);
+            float distance = GetPos().DistanceGlmVec3(born_pos.ToGlmVec3());
             if (room->OverBorder(GetPos(), gun_meta->bullet_rad())) {
                 if (IsBomb()) {
                     ProcBomb();