diff --git a/server/account/src/__tests__/migrations.test.ts b/server/account/src/__tests__/migrations.test.ts
new file mode 100644
index 00000000000..4e5dcd6b97f
--- /dev/null
+++ b/server/account/src/__tests__/migrations.test.ts
@@ -0,0 +1,42 @@
+//
+// Copyright © 2026 Hardcore Engineering Inc.
+//
+// Licensed under the Eclipse Public License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License. You may
+// obtain a copy of the License at https://www.eclipse.org/legal/epl-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import { getMigrations } from '../collections/postgres/migrations'
+
+describe('account db migrations', () => {
+  const splitStatements = (ddl: string): string[] =>
+    ddl
+      .split('\n')
+      .filter((line) => !line.trim().startsWith('--'))
+      .join('\n')
+      .split(';')
+      .map((s) => s.trim().replace(/\s+/g, ' '))
+      .filter((s) => s.length > 0)
+
+  it.each(['postgres', 'cockroach'] as const)(
+    'replaces the social_id primary key in a single statement (%s)',
+    (flavor) => {
+      const migration = getMigrations('global_account', flavor).find(
+        ([name]) => name === 'account_db_v2_social_id_pk_change'
+      )
+      expect(migration).toBeDefined()
+
+      const pkStatements = splitStatements(migration?.[1] ?? '').filter((s) => s.includes('social_id_pk'))
+      expect(pkStatements).toEqual([
+        'ALTER TABLE global_account.social_id DROP CONSTRAINT IF EXISTS social_id_pk, ADD CONSTRAINT social_id_pk PRIMARY KEY (_id)'
+      ])
+    }
+  )
+})
diff --git a/server/account/src/collections/postgres/migrations.ts b/server/account/src/collections/postgres/migrations.ts
index b8fd79c547c..ddc74cc1dbc 100644
--- a/server/account/src/collections/postgres/migrations.ts
+++ b/server/account/src/collections/postgres/migrations.ts
@@ -285,12 +285,11 @@ function getV2Migration2 (ns: string, flavor: DBFlavor): [string, string] {
     ALTER TABLE ${ns}.otp
     DROP CONSTRAINT IF EXISTS otp_social_id_fk;
 
-    -- Drop the existing primary key on social_id
-    ALTER TABLE ${ns}.social_id
-    DROP CONSTRAINT IF EXISTS social_id_pk;
-
-    -- Add the new primary key on _id
+    -- Replace the primary key on social_id with a new one on _id.
+    -- Both changes must be in a single statement: CockroachDB v25+ commits DDL
+    -- statements individually and rejects a table left without a primary key.
     ALTER TABLE ${ns}.social_id
+    DROP CONSTRAINT IF EXISTS social_id_pk,
     ADD CONSTRAINT social_id_pk PRIMARY KEY (_id);
     `
   ]