diff --git a/nexus/db-model/src/schema_versions.rs b/nexus/db-model/src/schema_versions.rs
index 5ceaf3167a6..cb5d244237e 100644
--- a/nexus/db-model/src/schema_versions.rs
+++ b/nexus/db-model/src/schema_versions.rs
@@ -17,7 +17,7 @@ use std::collections::BTreeMap;
 ///
 /// This must be updated when you change the database schema.  Refer to
 /// schema/crdb/README.adoc in the root of this repository for details.
-pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(65, 0, 0);
+pub const SCHEMA_VERSION: SemverVersion = SemverVersion::new(66, 0, 0);
 
 /// List of all past database schema versions, in *reverse* order
 ///
@@ -29,6 +29,7 @@ static KNOWN_VERSIONS: Lazy<Vec<KnownVersion>> = Lazy::new(|| {
         // |  leaving the first copy as an example for the next person.
         // v
         // KnownVersion::new(next_int, "unique-dirname-with-the-sql-files"),
+        KnownVersion::new(66, "add-instance-updater-lock"),
         KnownVersion::new(65, "region-replacement"),
         KnownVersion::new(64, "add-view-for-v2p-mappings"),
         KnownVersion::new(63, "remove-producer-base-route-column"),
diff --git a/schema/crdb/add-instance-updater-lock/up.sql b/schema/crdb/add-instance-updater-lock/up.sql
new file mode 100644
index 00000000000..76eae1f7231
--- /dev/null
+++ b/schema/crdb/add-instance-updater-lock/up.sql
@@ -0,0 +1,5 @@
+ALTER TABLE omicron.public.instance
+    ADD COLUMN IF NOT EXISTS updater_id UUID
+        DEFAULT null,
+    ADD COLUMN IF NOT EXISTS updater_gen INT
+        NOT NULL DEFAULT 0;
diff --git a/schema/crdb/dbinit.sql b/schema/crdb/dbinit.sql
index 17ea6d5510e..71c73596e75 100644
--- a/schema/crdb/dbinit.sql
+++ b/schema/crdb/dbinit.sql
@@ -1007,7 +1007,15 @@ CREATE TABLE IF NOT EXISTS omicron.public.instance (
     ncpus INT NOT NULL,
     memory INT NOT NULL,
     hostname STRING(63) NOT NULL,
-    boot_on_fault BOOL NOT NULL DEFAULT false
+    boot_on_fault BOOL NOT NULL DEFAULT false,
+
+    /* ID of the instance update saga that has locked this instance for
+     * updating, if one exists. */
+    updater_id UUID,
+
+    /* Generation of the instance updater lock */
+    updater_gen INT NOT NULL
+
 );
 
 -- Names for instances within a project should be unique