diff --git a/ursina/collider.py b/ursina/collider.py
index 05831610..dba48015 100644
--- a/ursina/collider.py
+++ b/ursina/collider.py
@@ -120,8 +120,12 @@ def __init__(self, entity, mesh=None, center=(0,0,0)):
                                 vertex_reader.setRow(vi)
                                 verts.append(vertex_reader.getData3())
 
+            # ursina uses a left handed y-up coordinate system
+            # but panda3d uses a right handed z-up coordinate system
+            verts = list(map(lambda v : Vec3(v[0],v[2],v[1]), verts))
+
             for i in range(0, len(verts)-3, 3):
-                p = CollisionPolygon(Vec3(verts[i+2]), Vec3(verts[i+1]), Vec3(verts[i]))
+                p = CollisionPolygon(verts[i+2], verts[i+1], verts[i])
                 self.collision_polygons.append(p)
 
         super().__init__(entity, self.collision_polygons)