diff --git a/control/json/group.hpp b/control/json/group.hpp
index 4057914..2d4a489 100644
--- a/control/json/group.hpp
+++ b/control/json/group.hpp
@@ -58,7 +58,7 @@
      *
      * @param[in] jsonObj - JSON object
      */
-    Group(const json& jsonObj);
+    explicit Group(const json& jsonObj);
 
     /**
      * Copy Constructor