diff --git a/spot/mc/bloemen_ec.hh b/spot/mc/bloemen_ec.hh
index 831c20b64..4f1bc78f5 100644
--- a/spot/mc/bloemen_ec.hh
+++ b/spot/mc/bloemen_ec.hh
@@ -103,12 +103,17 @@ namespace spot
     using shared_map = brick::hashset::FastConcurrent <uf_element*,
                                                        uf_element_hasher>;
 
+    iterable_uf_ec(const iterable_uf_ec<State, StateHash, StateEqual>& uf):
+      map_(uf.map_), tid_(uf.tid_), size_(std::thread::hardware_concurrency()),
+      nb_th_(std::thread::hardware_concurrency()), inserted_(0),
+      p_(sizeof(uf_element))
+    { }
+
     iterable_uf_ec(shared_map& map, unsigned tid):
       map_(map), tid_(tid), size_(std::thread::hardware_concurrency()),
       nb_th_(std::thread::hardware_concurrency()), inserted_(0),
       p_(sizeof(uf_element))
-    {
-    }
+    { }
 
     ~iterable_uf_ec() {}
 
@@ -440,6 +445,8 @@ namespace spot
     }
 
   private:
+    iterable_uf_ec() = default;
+
     shared_map map_;      ///< \brief Map shared by threads copy!
     unsigned tid_;        ///< \brief The Id of the current thread
     unsigned size_;       ///< \brief Maximum number of thread
@@ -455,6 +462,8 @@ namespace spot
            typename StateHash, typename StateEqual>
   class swarmed_bloemen_ec
   {
+  private:
+    swarmed_bloemen_ec() = delete;
   public:
 
     using uf = iterable_uf_ec<State, StateHash, StateEqual>;
@@ -483,6 +492,8 @@ namespace spot
                     "error: does not match the kripkecube requirements");
     }
 
+    ~swarmed_bloemen_ec() = default;
+
     void run()
     {
       setup();