diff --git a/packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-builder/services/workspace-entity-migration-builder.service.ts b/packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-builder/services/workspace-entity-migration-builder.service.ts
index 2a73347cc5..fe3c167847 100644
--- a/packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-builder/services/workspace-entity-migration-builder.service.ts
+++ b/packages/twenty-server/src/engine/workspace-manager/workspace-migration/workspace-migration-builder/services/workspace-entity-migration-builder.service.ts
@@ -390,6 +390,16 @@ export abstract class WorkspaceEntityMigrationBuilderService<
       ];
     }
 
+    if (universalIdentifier !== universalIdentifier.toLowerCase()) {
+      return [
+        {
+          code: FlatEntityMapsExceptionCode.ENTITY_MALFORMED,
+          message: `Invalid universalIdentifier: "${universalIdentifier}" must be lowercase`,
+          value: universalIdentifier,
+        },
+      ];
+    }
+
     return [];
   }