diff --git a/server/gameserver/collider.cc b/server/gameserver/collider.cc
index 84f11303..689f97fb 100644
--- a/server/gameserver/collider.cc
+++ b/server/gameserver/collider.cc
@@ -74,6 +74,12 @@ bool ColliderComponent::Intersect(ColliderComponent* b)
             case CT_Arc:
                 {
                     ArcCollider* b_arc = (ArcCollider*)b;
+                    #if 0
+                    return a8::IntersectAabbArc(a_aabb->owner->GetPos() + a_aabb->_min,
+                                                a_aabb->owner->GetPos() + a_aabb->_max,
+                                                b_arc->owner->GetPos(),
+                                                b_arc->width);
+                    #endif
                 }
                 break;
             }
@@ -104,6 +110,17 @@ bool ColliderComponent::Intersect(ColliderComponent* b)
                                                       b_circle->rad);
                 }
                 break;
+            case CT_Arc:
+                {
+                    ArcCollider* b_arc = (ArcCollider*)b;
+                    #if 0
+                    return a8::IntersectCircleArc(a_circle->owner->GetPos(),
+                                                  a_circle->rad,
+                                                  b_arc->owner->GetPos(),
+                                                  b_arc->width);
+                    #endif
+                }
+                break;
             }
         }
         break;
diff --git a/third_party/a8engine b/third_party/a8engine
index cc57f691..ab36720b 160000
--- a/third_party/a8engine
+++ b/third_party/a8engine
@@ -1 +1 @@
-Subproject commit cc57f69109cae63a1cfda69df474ffc328c012cc
+Subproject commit ab36720b8e2b61fd70cc288d3708f88a94d1ca6b