diff --git a/ubi/activation_ubi.hpp b/ubi/activation_ubi.hpp
index a6ef436..957ee06 100644
--- a/ubi/activation_ubi.hpp
+++ b/ubi/activation_ubi.hpp
@@ -2,6 +2,8 @@
 
 #include "activation.hpp"
 
+#include <string>
+
 namespace openpower
 {
 namespace software
diff --git a/ubi/item_updater_ubi.hpp b/ubi/item_updater_ubi.hpp
index 183daac..ccd8e57 100644
--- a/ubi/item_updater_ubi.hpp
+++ b/ubi/item_updater_ubi.hpp
@@ -2,6 +2,8 @@
 
 #include "item_updater.hpp"
 
+#include <string>
+
 namespace openpower
 {
 namespace software
diff --git a/ubi/watch.hpp b/ubi/watch.hpp
index 4d195a3..2e0ec17 100644
--- a/ubi/watch.hpp
+++ b/ubi/watch.hpp
@@ -5,6 +5,7 @@
 
 #include <functional>
 #include <memory>
+#include <string>
 
 namespace openpower
 {