diff --git a/types/index.d.ts b/types/index.d.ts
index 90cdcf4..935781c 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -17,6 +17,11 @@ interface DotenvOptions {
 
 type EnvSchema = typeof envSchema
 
+type FluentSchema = {
+  isFluentSchema: boolean;
+  isFluentJSONSchema: boolean;
+}
+
 declare namespace envSchema {
   export type { JSONSchemaType }
 
@@ -25,7 +30,7 @@ declare namespace envSchema {
   }
 
   export type EnvSchemaOpt<T = EnvSchemaData> = {
-    schema?: JSONSchemaType<T> | AnySchema;
+    schema?: JSONSchemaType<T> | AnySchema | FluentSchema;
     data?: [EnvSchemaData, ...EnvSchemaData[]] | EnvSchemaData;
     env?: boolean;
     dotenv?: boolean | DotenvOptions;
diff --git a/types/index.tst.ts b/types/index.tst.ts
index 2cc1ff7..9004ae3 100644
--- a/types/index.tst.ts
+++ b/types/index.tst.ts
@@ -7,6 +7,7 @@ import envSchema, {
   default as envSchemaDefault,
 } from '.'
 import Ajv, { KeywordDefinition, JSONSchemaType } from 'ajv'
+import S from 'fluent-json-schema'
 import { Static, Type } from 'typebox'
 
 interface EnvData {
@@ -46,6 +47,11 @@ const optWithSchemaTypebox: EnvSchemaOpt = {
 }
 expect(optWithSchemaTypebox).type.toBe<EnvSchemaOpt>()
 
+const optWithFluentSchema: EnvSchemaOpt = {
+  schema: S.object().prop('PORT', S.number().default(3000).required()),
+}
+expect(optWithFluentSchema).type.toBe<EnvSchemaOpt>()
+
 const optWithSchemaWithType: EnvSchemaOpt<EnvData> = {
   schema: schemaWithType,
 }
@@ -113,5 +119,13 @@ expect(envSchemaWithType).type.toBe<EnvData>()
 const envSchemaTypebox = envSchema<SchemaTypebox>({ schema: schemaTypebox })
 expect(envSchemaTypebox).type.toBe<SchemaTypebox>()
 
+const envSchemaFluent = envSchema<EnvData>({
+  schema: S.object<EnvData>().prop(
+    'PORT',
+    S.number().default(3000).required()
+  ),
+})
+expect(envSchemaFluent).type.toBe<EnvData>()
+
 expect(keywords.separator).type.toBe<KeywordDefinition>()
 expect(envSchema.keywords.separator).type.toBe<KeywordDefinition>()