diff --git a/coderd/database/dump.sql b/coderd/database/dump.sql
index aa481b8400a9f..3479bb1bdc1e7 100644
--- a/coderd/database/dump.sql
+++ b/coderd/database/dump.sql
@@ -287,7 +287,7 @@ CREATE TABLE workspace_agents (
     disconnected_at timestamp with time zone,
     resource_id uuid NOT NULL,
     auth_token uuid NOT NULL,
-    auth_instance_id character varying(64),
+    auth_instance_id character varying,
     architecture character varying(64) NOT NULL,
     environment_variables jsonb,
     operating_system character varying(64) NOT NULL,
diff --git a/coderd/database/migrations/000031_agent_auth_instance_id.down.sql b/coderd/database/migrations/000031_agent_auth_instance_id.down.sql
new file mode 100644
index 0000000000000..9500f140e7f87
--- /dev/null
+++ b/coderd/database/migrations/000031_agent_auth_instance_id.down.sql
@@ -0,0 +1 @@
+ALTER TABLE workspace_agents ALTER COLUMN auth_instance_id TYPE character varying(64);
diff --git a/coderd/database/migrations/000031_agent_auth_instance_id.up.sql b/coderd/database/migrations/000031_agent_auth_instance_id.up.sql
new file mode 100644
index 0000000000000..c45a905b4ccd4
--- /dev/null
+++ b/coderd/database/migrations/000031_agent_auth_instance_id.up.sql
@@ -0,0 +1 @@
+ALTER TABLE workspace_agents ALTER COLUMN auth_instance_id TYPE character varying;