diff --git a/src/event.hpp b/src/event.hpp
index 2116977..7ce764b 100644
--- a/src/event.hpp
+++ b/src/event.hpp
@@ -5,6 +5,7 @@
 
 #include <phosphor-logging/log.hpp>
 #include <sstream>
+#include <string>
 
 namespace phosphor
 {