diff --git a/src/branch2.cpp b/src/branch2.cpp
index ec10a9f9..0b4a539c 100644
--- a/src/branch2.cpp
+++ b/src/branch2.cpp
@@ -18,6 +18,11 @@ Branch2::Branch2()
 
 }
 
+Branch2::Branch2(Branch2 const &v_)
+{
+  
+}
+
 Branch2::Branch2(toml::value const &v_)
   : mode(Mode::RW)
 {