diff --git a/ledlayout.hpp b/ledlayout.hpp
index 90b333c..f12e0b5 100644
--- a/ledlayout.hpp
+++ b/ledlayout.hpp
@@ -2,6 +2,7 @@
 
 #include <map>
 #include <set>
+#include <string>
 
 namespace phosphor
 {