diff --git a/src/XrdOssCsi/XrdOssCsiPages.hh b/src/XrdOssCsi/XrdOssCsiPages.hh
index 852a3add6f9..cd1c1b4a392 100644
--- a/src/XrdOssCsi/XrdOssCsiPages.hh
+++ b/src/XrdOssCsi/XrdOssCsiPages.hh
@@ -38,6 +38,7 @@
 #include "XrdOssCsiRanges.hh"
 #include <memory>
 #include <mutex>
+#include <string>
 #include <utility>
 #include <cinttypes>
 #include <cstdio>