diff --git a/include/register.h b/include/register.h
index 67220dd..760fa3a 100644
--- a/include/register.h
+++ b/include/register.h
@@ -28,7 +28,7 @@ struct Register {
   public:
     static constexpr std::size_t _Bit_Len = _Len;
 
-    explicit Register() : _M_old(), _M_new(), _M_assigned() {}
+    Register() : _M_old(), _M_new(), _M_assigned() {}
 
     Register(Register &&) = delete;
     Register(const Register &) = delete;
diff --git a/include/tools b/include/tools
index 7873af4..efbaa7e 100644
--- a/include/tools
+++ b/include/tools
@@ -15,3 +15,4 @@ using dark::Register;
 
 using dark::SyncTags;
 using dark::sync_member;
+using dark::Visitor;
diff --git a/include/wire.h b/include/wire.h
index 5c1bf7e..581ddc2 100644
--- a/include/wire.h
+++ b/include/wire.h
@@ -75,7 +75,7 @@ struct Wire {
   public:
     static constexpr std::size_t _Bit_Len = _Len;
 
-    explicit Wire() :
+    Wire() :
         _M_func(new details::EmptyWire),
         _M_cache(), _M_holds(), _M_assigned() {}