diff --git a/include/hpp/fcl/collision_data.h b/include/hpp/fcl/collision_data.h
index fdc9993acfe47bfe90f40230b8f9cb1730c8b0ec..db61106193549b0d2af496c562fe01dd42ed2782 100644
--- a/include/hpp/fcl/collision_data.h
+++ b/include/hpp/fcl/collision_data.h
@@ -129,6 +129,11 @@ struct Contact
             && pos == other.pos
             && penetration_depth == other.penetration_depth;
   }
+  
+  bool operator != (const Contact& other) const
+  {
+    return !(*this == other);
+  }
 };
 
 struct CollisionResult;