diff --git a/compute-type-value/evaluate.test.ts b/compute-type-value/evaluate.test.ts
index 884f121..1851559 100644
--- a/compute-type-value/evaluate.test.ts
+++ b/compute-type-value/evaluate.test.ts
@@ -3,7 +3,7 @@ import * as fs from "node:fs";
 import { describe, expect, it } from "vitest";
 import { evaluate } from "./evaluate";
 
-describe("evaluate type", () => {
+describe("evaluate type .ts", () => {
   it("standard", () => {
     const type = `
     export type Handler = 1;
@@ -46,3 +46,17 @@ describe("evaluate type", () => {
     expect(r2).toBe(1);
   });
 });
+
+describe("evaluate type .d.ts", () => {
+  it("standard", () => {
+    const type = `
+    export type Handler = 1;
+    `.trim();
+    const fileName = `/tmp/${randomUUID()}.d.ts`;
+    fs.writeFileSync(fileName, type);
+
+    const result = evaluate(fileName, "Handler", {});
+
+    expect(result).toBe(1);
+  });
+});
diff --git a/compute-type-value/evaluate.ts b/compute-type-value/evaluate.ts
index 96570ce..eeda3a3 100644
--- a/compute-type-value/evaluate.ts
+++ b/compute-type-value/evaluate.ts
@@ -3,18 +3,14 @@ import {
   type LiteralType,
   ModuleKind,
   NewLineKind,
-  NodeBuilderFlags,
   NodeFlags,
-  type PseudoBigInt,
   ScriptTarget,
   SyntaxKind,
-  TypeFormatFlags,
   createCompilerHost,
   createPrinter,
   createProgram,
   createSourceFile,
   factory,
-  isLiteralTypeNode,
   isTypeAliasDeclaration,
 } from "typescript";
 
@@ -43,7 +39,7 @@ function createMain(
               ),
             ]),
           ),
-          factory.createStringLiteral(entryFile),
+          factory.createStringLiteral(entryFile.replace(/\.[^/.]+$/, "")),
         ),
         factory.createTypeAliasDeclaration(
           undefined,
diff --git a/compute-type-value/sampleIndex.ts b/compute-type-value/sampleIndex.ts
index 4e6f442..bbce1ee 100644
--- a/compute-type-value/sampleIndex.ts
+++ b/compute-type-value/sampleIndex.ts
@@ -1,4 +1,4 @@
-import type { Sum } from "./sampleSum";
+import type { Sum } from "./sampleSum.d.ts";
 
 type Event = {
   n1: number;