diff --git a/src/ser/impl.ts b/src/ser/impl.ts
index 13fe7cb..74f1e26 100644
--- a/src/ser/impl.ts
+++ b/src/ser/impl.ts
@@ -30,7 +30,6 @@ function getSerialize<T, U>(value: U, registry: Registry): Serialize<T> {
 
   return registry.serializers.get(PrimitivePrototype[typeof value]) || defaultSerialize as Serialize<T>
 }
-
 function defaultSerialize<T, U, S extends ISerializer<T>>(serializer: S, value: U): T {
   switch (typeof value) {
     case 'string': return serializer.serializeString(value)
diff --git a/src/ser/interface.ts b/src/ser/interface.ts
index 9fd5462..332c24d 100644
--- a/src/ser/interface.ts
+++ b/src/ser/interface.ts
@@ -77,6 +77,6 @@ export class Serializer<T> implements ISerializer<T> {
 }
 
 export interface Serialize<T> {
-  <U, S extends ISerializer<U>>(serializer: S, value: T): U
+  <U>(serializer: ISerializer<T>, value: U): T
 }