diff --git a/packages/backend/src/misc/is-duplicate-key-value-error.ts b/packages/backend/src/misc/is-duplicate-key-value-error.ts
index 04ff191e4..f5343d187 100644
--- a/packages/backend/src/misc/is-duplicate-key-value-error.ts
+++ b/packages/backend/src/misc/is-duplicate-key-value-error.ts
@@ -1,3 +1,5 @@
+import { QueryFailedError } from 'typeorm';
+
 export function isDuplicateKeyValueError(e: unknown | Error): boolean {
-	return (e as any).message && (e as Error).message.startsWith('duplicate key value');
+	return e instanceof QueryFailedError && e.driverError.code === '23505';
 }