diff --git a/phosphor-regulators/src/actions/not_action.hpp b/phosphor-regulators/src/actions/not_action.hpp
index 824a763..762f5b5 100644
--- a/phosphor-regulators/src/actions/not_action.hpp
+++ b/phosphor-regulators/src/actions/not_action.hpp
@@ -19,6 +19,7 @@
 #include "action_environment.hpp"
 
 #include <memory>
+#include <string>
 #include <utility>
 
 namespace phosphor::power::regulators
@@ -79,6 +80,16 @@
         return action;
     }
 
+    /**
+     * Returns a string description of this action.
+     *
+     * @return description of action
+     */
+    virtual std::string toString() const override
+    {
+        return "not: { ... }";
+    }
+
   private:
     /**
      * Action to execute.