diff --git a/include/c11log/formatter.h b/include/c11log/formatter.h
index f7b2b5fd..ee2db989 100644
--- a/include/c11log/formatter.h
+++ b/include/c11log/formatter.h
@@ -6,6 +6,7 @@ namespace c11log
 class formatter
 {
 public:
+    virtual formatter() {}
     virtual void format(details::log_msg& msg) = 0;
 };
 }