diff --git a/dist/ioptions.d.ts b/dist/ioptions.d.ts
index 8a0dfcc..e0001c7 100644
--- a/dist/ioptions.d.ts
+++ b/dist/ioptions.d.ts
@@ -1,10 +1,10 @@
 import { tsModule } from "./tsproxy";
 import * as tsTypes from "typescript";
-export interface CustomTransformer {
+export interface ICustomTransformer {
     before?: tsTypes.TransformerFactory<tsTypes.SourceFile>;
     after?: tsTypes.TransformerFactory<tsTypes.SourceFile>;
 }
-export declare type TransformerFactoryCreator = (ls: tsTypes.LanguageService) => tsTypes.CustomTransformers | CustomTransformer;
+export declare type TransformerFactoryCreator = (ls: tsTypes.LanguageService) => tsTypes.CustomTransformers | ICustomTransformer;
 export interface IOptions {
     include: string | string[];
     exclude: string | string[];
diff --git a/src/ioptions.ts b/src/ioptions.ts
index 2f1be99..2481f4b 100644
--- a/src/ioptions.ts
+++ b/src/ioptions.ts
@@ -1,13 +1,13 @@
 import { tsModule } from "./tsproxy";
 import * as tsTypes from "typescript";
 
-export interface CustomTransformer 
+export interface ICustomTransformer
 {
 	before?: tsTypes.TransformerFactory<tsTypes.SourceFile>;
 	after?: tsTypes.TransformerFactory<tsTypes.SourceFile>;
 }
 
-export type TransformerFactoryCreator = (ls: tsTypes.LanguageService) => tsTypes.CustomTransformers | CustomTransformer;
+export type TransformerFactoryCreator = (ls: tsTypes.LanguageService) => tsTypes.CustomTransformers | ICustomTransformer;
 
 export interface IOptions
 {