diff --git a/src/state.hpp b/src/state.hpp
index 8dd65f66..2bda2555 100644
--- a/src/state.hpp
+++ b/src/state.hpp
@@ -2,6 +2,9 @@
 
 class State
 {
+public:
+  State();
+  
 public:
   Branches2 branches;
 };