diff --git a/types/yup/index.d.ts b/types/yup/index.d.ts
index 7e03517143..58067b926b 100644
--- a/types/yup/index.d.ts
+++ b/types/yup/index.d.ts
@@ -106,6 +106,7 @@ export interface StringSchemaConstructor {
 }
 
 export interface StringSchema extends Schema<string> {
+    length(limit: number | Ref, message?: TestOptionsMessage): StringSchema;
     min(limit: number | Ref, message?: TestOptionsMessage): StringSchema;
     max(limit: number | Ref, message?: TestOptionsMessage): StringSchema;
     matches(
diff --git a/types/yup/yup-tests.ts b/types/yup/yup-tests.ts
index fdead13b2b..0c515ef78c 100644
--- a/types/yup/yup-tests.ts
+++ b/types/yup/yup-tests.ts
@@ -292,6 +292,8 @@ strSchema.isValid("hello"); // => true
 strSchema.required();
 strSchema.required("req");
 strSchema.required(() => "req");
+strSchema.length(5, "message");
+strSchema.length(5, () => "message");
 strSchema.min(5, "message");
 strSchema.min(5, () => "message");
 strSchema.max(5, "message");