diff --git a/prisma/migrations/20251203192130_added_the_option_of_null_to_is_dark_mode/migration.sql b/prisma/migrations/20251203192130_added_the_option_of_null_to_is_dark_mode/migration.sql
new file mode 100644
index 0000000..6bc061e
--- /dev/null
+++ b/prisma/migrations/20251203192130_added_the_option_of_null_to_is_dark_mode/migration.sql
@@ -0,0 +1,5 @@
+-- CreateEnum
+CREATE TYPE "modules" AS ENUM ('timesheets', 'timesheets_approval', 'employee_list', 'employee_management', 'personal_profile', 'dashboard');
+
+-- AlterTable
+ALTER TABLE "preferences" ALTER COLUMN "is_dark_mode" DROP NOT NULL;
diff --git a/prisma/schema.prisma b/prisma/schema.prisma
index 5dc2348..39d9148 100644
--- a/prisma/schema.prisma
+++ b/prisma/schema.prisma
@@ -53,7 +53,7 @@ model Employees {
   supervisor    Employees? @relation("EmployeeSupervisor", fields: [supervisor_id], references: [id])
   supervisor_id Int?
 
-  external_payroll_id Int @default(autoincrement())
+  external_payroll_id Int       @default(autoincrement())
   company_code        Int
   first_work_day      DateTime  @db.Date
   last_work_day       DateTime? @db.Date
@@ -347,12 +347,12 @@ model Preferences {
   user    Users  @relation("UserPreferences", fields: [user_id], references: [id])
   user_id String @unique @db.Uuid
 
-  notifications              Boolean @default(true)
+  notifications              Boolean  @default(true)
   is_dark_mode               Boolean? @default(false)
-  display_language           String  @default("fr-FR") //'fr-FR' | 'en-CA';
-  is_lefty_mode              Boolean @default(false)
-  is_employee_list_grid      Boolean @default(true)
-  is_timesheet_approval_grid Boolean @default(true)
+  display_language           String   @default("fr-FR") //'fr-FR' | 'en-CA';
+  is_lefty_mode              Boolean  @default(false)
+  is_employee_list_grid      Boolean  @default(true)
+  is_timesheet_approval_grid Boolean  @default(true)
 
   @@map("preferences")
 }
diff --git a/src/identity-and-account/preferences/dtos/preferences.dto.ts b/src/identity-and-account/preferences/dtos/preferences.dto.ts
index 81a8dd6..e470dad 100644
--- a/src/identity-and-account/preferences/dtos/preferences.dto.ts
+++ b/src/identity-and-account/preferences/dtos/preferences.dto.ts
@@ -8,7 +8,7 @@ export enum DisplayLanguage {
 export class PreferencesDto {
     @IsInt() id: number;
     @IsBoolean() notifications: boolean;
-    @IsOptional() @IsBoolean() is_dark_mode?: boolean;
+    @IsOptional() @IsBoolean() is_dark_mode?: boolean | null;
     @IsEnum(DisplayLanguage) display_language: string;
     @IsBoolean() is_lefty_mode: boolean;
     @IsBoolean() is_employee_list_grid: boolean;