diff --git a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.spec.ts b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.spec.ts
index 69db0fcd..0a04e1c1 100644
--- a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.spec.ts
+++ b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.spec.ts
@@ -220,6 +220,14 @@ describe('Check "filter" zod schema', () => {
       },
       relation: null,
     };
+    const check9: FilterQuerySchema = {
+      target: {
+        createdAt: {
+          eq: 'null',
+        },
+      },
+      relation: null,
+    };
 
     const checkArray = [
       check1,
@@ -235,6 +243,10 @@ describe('Check "filter" zod schema', () => {
       const result = filterQuerySchema.parse(check);
       expect(result).toEqual(check);
     }
+    const result = filterQuerySchema.parse(check9);
+    expect(result.target!.createdAt!.eq).toEqual(null);
+    result.target!.createdAt!.eq = 'null';
+    expect(result).toEqual(check9);
   });
 
   it('Invalid schema', () => {
diff --git a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.ts b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.ts
index fec4b032..99f9c7cb 100644
--- a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.ts
+++ b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-query-schema/filter.ts
@@ -2,10 +2,12 @@ import {
   z,
   ZodArray,
   ZodEffects,
+  ZodLiteral,
   ZodNullable,
   ZodObject,
   ZodOptional,
   ZodString,
+  ZodUnion,
 } from 'zod';
 import {
   arrayItemStringLongerThan,
@@ -41,15 +43,21 @@ import {
   ZodFilterRelationSchema,
 } from '../zod-input-query-schema/filter';
 
-type ZodForString = ZodEffects<ZodString>;
-const zodForString: ZodForString = z.string().refine(stringLongerThan(), {
-  message: 'String should be not empty',
-});
+type ZodForString = ZodUnion<
+  [ZodEffects<ZodLiteral<'null'>, null, 'null'>, ZodEffects<ZodString>]
+>;
+
+const zodForString: ZodForString = z.union([
+  z.literal('null').transform(() => null),
+  z.string().refine(stringLongerThan(), {
+    message: 'String should be not empty',
+  }),
+]);
 
 type ZodForStringArray = ZodEffects<
   ZodArray<ZodForString, 'atleastone'>,
-  string[],
-  string[]
+  [string | null, ...(string | null)[]],
+  [string, ...string[]]
 >;
 const zodForStringArray: ZodForStringArray = zodForString
   .array()
diff --git a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-utils.ts b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-utils.ts
index eec27e43..f265e25b 100644
--- a/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-utils.ts
+++ b/libs/json-api/json-api-nestjs/src/lib/helper/zod/zod-utils.ts
@@ -14,14 +14,15 @@ export const stringLongerThan =
 
 export const arrayItemStringLongerThan =
   (length = 0) =>
-  (array: [string, ...string[]]) => {
+  (array: [string | null, ...(string | null)[]]) => {
     const checkFunction = stringLongerThan(length);
-    return !array.some((i) => !checkFunction(i));
+    return !array.some((i) => i !== null && !checkFunction(i));
   };
 
 export const stringMustBe =
   (type: TypeField = TypeField.string) =>
-  (inputString: string) => {
+  (inputString: string | null) => {
+    if (inputString === null) return true;
     switch (type) {
       case TypeField.boolean:
         return inputString === 'true' || inputString === 'false';
diff --git a/libs/json-api/json-api-nestjs/src/lib/mixin/service/typeorm-utils.service.spec.ts b/libs/json-api/json-api-nestjs/src/lib/mixin/service/typeorm-utils.service.spec.ts
index 2777d323..96aa3b5e 100644
--- a/libs/json-api/json-api-nestjs/src/lib/mixin/service/typeorm-utils.service.spec.ts
+++ b/libs/json-api/json-api-nestjs/src/lib/mixin/service/typeorm-utils.service.spec.ts
@@ -26,7 +26,6 @@ import {
 } from '../../constants';
 import { TypeormUtilsService } from './typeorm-utils.service';
 import {
-  ObjectTyped,
   PostData,
   PostRelationshipData,
   Query,
@@ -253,7 +252,7 @@ describe('TypeormUtilsService', () => {
         `test for ${filterOperand}`;
       const valueTestArray = (
         filterOperand: FilterOperand.nin | FilterOperand.in
-      ) => [valueTest(filterOperand)];
+      ): [string, ...string[]] => [valueTest(filterOperand)];
 
       const query = getDefaultQuery<Users>();
       query.filter.target = {
@@ -429,9 +428,10 @@ describe('TypeormUtilsService', () => {
         createdAt: {
           [FilterOperand.eq]: 'test1',
           [FilterOperand.ne]: 'test2',
-          [FilterOperand.nin]: ['test3'],
+          [FilterOperand.nin]: ['test3'] as [string, ...string[]],
         },
       };
+
       query.filter.relation = {
         roles: conditional,
       };