diff --git a/catalogue/TapePool.hpp b/catalogue/TapePool.hpp
index 7ca30f058e493943f219c121a38d07c4f6449f80..5de6f27e89aa695668ed74772266eb97ff9ae15a 100644
--- a/catalogue/TapePool.hpp
+++ b/catalogue/TapePool.hpp
@@ -23,6 +23,7 @@
 #include <string>
 
 #include "common/dataStructures/EntryLog.hpp"
+#include "common/optional.hpp"
 
 namespace cta {
 namespace catalogue {
@@ -99,6 +100,11 @@ struct TapePool {
    */
   uint64_t nbPhysicalFiles;
 
+  /**
+   * Optional value used by the tape pool supply mechanism.
+   */
+  cta::optional<std::string> supply;
+
   /**
    * The creation log.
    */