diff --git a/lib/plugin/utils/ast-utils.ts b/lib/plugin/utils/ast-utils.ts
index 2078a1d21..162be3653 100644
--- a/lib/plugin/utils/ast-utils.ts
+++ b/lib/plugin/utils/ast-utils.ts
@@ -46,6 +46,10 @@ export function isStringLiteral(type: Type) {
   return hasFlag(type, TypeFlags.StringLiteral) && !type.isUnion();
 }
 
+export function isStringMapping(type: Type) {
+  return hasFlag(type, TypeFlags.StringMapping);
+}
+
 export function isNumber(type: Type) {
   return hasFlag(type, TypeFlags.Number);
 }
diff --git a/lib/plugin/utils/plugin-utils.ts b/lib/plugin/utils/plugin-utils.ts
index 3608931f3..138a7f85e 100644
--- a/lib/plugin/utils/plugin-utils.ts
+++ b/lib/plugin/utils/plugin-utils.ts
@@ -13,7 +13,8 @@ import {
   isInterface,
   isNumber,
   isString,
-  isStringLiteral
+  isStringLiteral,
+  isStringMapping
 } from './ast-utils';
 
 export function getDecoratorOrUndefinedByNames(
@@ -65,7 +66,7 @@ export function getTypeReferenceAsString(
   if (isBigInt(type)) {
     return { typeName: BigInt.name, arrayDepth };
   }
-  if (isString(type) || isStringLiteral(type)) {
+  if (isString(type) || isStringLiteral(type) || isStringMapping(type)) {
     return { typeName: String.name, arrayDepth };
   }
   if (isPromiseOrObservable(getText(type, typeChecker))) {
diff --git a/test/plugin/fixtures/project/cats/classes/cat.class.ts b/test/plugin/fixtures/project/cats/classes/cat.class.ts
index a70189ebd..7a875ab49 100644
--- a/test/plugin/fixtures/project/cats/classes/cat.class.ts
+++ b/test/plugin/fixtures/project/cats/classes/cat.class.ts
@@ -25,4 +25,12 @@ export class Cat {
   enum: LettersEnum;
 
   enumArr: LettersEnum;
+
+  uppercaseString: Uppercase<string>;
+  
+  lowercaseString: Lowercase<string>;
+
+  capitalizeString: Capitalize<string>;
+
+  uncapitalizeString: Uncapitalize<string>;
 }
diff --git a/test/plugin/fixtures/serialized-meta.fixture.ts b/test/plugin/fixtures/serialized-meta.fixture.ts
index b87554c35..9bd46decf 100644
--- a/test/plugin/fixtures/serialized-meta.fixture.ts
+++ b/test/plugin/fixtures/serialized-meta.fixture.ts
@@ -64,7 +64,11 @@ export default async () => {
               enumArr: {
                 required: true,
                 enum: t['./cats/dto/pagination-query.dto'].LettersEnum
-              }
+              },
+              uppercaseString: { required: true, type: () => String },
+              lowercaseString: { required: true, type: () => String },
+              capitalizeString: { required: true, type: () => String },
+              uncapitalizeString: { required: true, type: () => String }
             }
           }
         ],