diff --git a/common/action.h b/common/action.h
index fd82c2d..d32322c 100644
--- a/common/action.h
+++ b/common/action.h
@@ -98,7 +98,7 @@
   virtual void PerformAction() = 0;
 
   // Called on ActionProcess::ActionComplete() by ActionProcessor.
-  virtual void ActionCompleted(ErrorCode code) {}
+  virtual void ActionCompleted([[maybe_unused]] ErrorCode code) {}
 
   // Called by the ActionProcessor to tell this Action which processor
   // it belongs to.