diff --git a/thin-provisioning/device_tree.cc b/thin-provisioning/device_tree.cc
index 4837cb7..4b4e0dd 100644
--- a/thin-provisioning/device_tree.cc
+++ b/thin-provisioning/device_tree.cc
@@ -54,6 +54,13 @@ namespace thin_provisioning {
 			  snapshotted_time_(0) {
 		}
 
+		device_details::device_details(uint64_t tid, uint32_t time)
+			: mapped_blocks_(0),
+			  transaction_id_(tid),
+			  creation_time_(time),
+			  snapshotted_time_(time) {
+		}
+
 		void
 		device_details_traits::unpack(device_details_disk const &disk, device_details &value)
 		{
diff --git a/thin-provisioning/device_tree.h b/thin-provisioning/device_tree.h
index d284ac5..d7178cd 100644
--- a/thin-provisioning/device_tree.h
+++ b/thin-provisioning/device_tree.h
@@ -17,6 +17,7 @@ namespace thin_provisioning {
 
 		struct device_details {
 			device_details();
+			device_details(uint64_t tid, uint32_t time);
 
 			uint64_t mapped_blocks_;
 			uint64_t transaction_id_;  /* when created */