diff --git a/schemas/ispyb/updates/2025_03_05_Dewar_dewarRegistryId.sql b/schemas/ispyb/updates/2025_03_05_Dewar_dewarRegistryId.sql
new file mode 100644
index 0000000..ba7e41f
--- /dev/null
+++ b/schemas/ispyb/updates/2025_03_05_Dewar_dewarRegistryId.sql
@@ -0,0 +1,11 @@
+INSERT IGNORE INTO SchemaStatus (scriptName, schemaStatus) VALUES ('2025_03_05_Dewar_dewarRegistryId.sql', 'ONGOING');
+
+ALTER TABLE Dewar
+  ADD dewarRegistryId int(11) unsigned COMMENT 'Reference to the registered dewar i.e. the physical item',
+  ADD CONSTRAINT Dewar_fk_dewarRegistryId
+  FOREIGN KEY (dewarRegistryId)
+      REFERENCES DewarRegistry(dewarRegistryId)
+          ON DELETE CASCADE
+          ON UPDATE CASCADE;
+
+UPDATE SchemaStatus SET schemaStatus = 'DONE' WHERE scriptName = '2025_03_05_Dewar_dewarRegistryId.sql';