diff --git a/fsm.hpp b/fsm.hpp
index 28dcddd..5898ea4 100644
--- a/fsm.hpp
+++ b/fsm.hpp
@@ -18,7 +18,7 @@ public:
   template<typename... Types>
   void event(E event, Types... args);
 
-  void state(S next_state)
+  void state(S next_state) {
     _state = next_state;
   }