diff --git a/__tests__/fixtures/mocks.ts b/__tests__/fixtures/mocks.ts
index fc2a1dbb..f6768e9b 100644
--- a/__tests__/fixtures/mocks.ts
+++ b/__tests__/fixtures/mocks.ts
@@ -111,10 +111,12 @@ export const createOctokitMock = (
   rest: {
     repos: {
       get: jest
-        .fn<RestEndpointMethodTypes['repos']['get']['response']>()
+        .fn<
+          () => Promise<RestEndpointMethodTypes['repos']['get']['response']>
+        >()
         .mockResolvedValue({
           data: { owner: { type: ownerType } }
-        })
+        } as RestEndpointMethodTypes['repos']['get']['response'])
     }
   }
 })
diff --git a/__tests__/index.test.ts b/__tests__/index.test.ts
index 9681388f..38778768 100644
--- a/__tests__/index.test.ts
+++ b/__tests__/index.test.ts
@@ -2,8 +2,8 @@ import { jest } from '@jest/globals'
 
 // Mock functions
 const mockRun = jest.fn()
-const mockGetInput = jest.fn()
-const mockGetBooleanInput = jest.fn()
+const mockGetInput = jest.fn<(name: string) => string>()
+const mockGetBooleanInput = jest.fn<(name: string) => boolean>()
 
 // Mock @actions/core
 jest.unstable_mockModule('@actions/core', () => ({
diff --git a/package-lock.json b/package-lock.json
index ac1d5af9..ff3f2106 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -33,7 +33,7 @@
         "nock": "^13.5.6",
         "prettier": "^3.8.3",
         "ts-jest": "^29.4.9",
-        "typescript": "^5.9.3",
+        "typescript": "^6.0.3",
         "typescript-eslint": "^8.58.2",
         "undici": "^7.24.4"
       },
@@ -9769,9 +9769,9 @@
       }
     },
     "node_modules/typescript": {
-      "version": "5.9.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
-      "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
+      "version": "6.0.3",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-6.0.3.tgz",
+      "integrity": "sha512-y2TvuxSZPDyQakkFRPZHKFm+KKVqIisdg9/CZwm9ftvKXLP8NRWj38/ODjNbr43SsoXqNuAisEf1GdCxqWcdBw==",
       "dev": true,
       "license": "Apache-2.0",
       "bin": {
diff --git a/package.json b/package.json
index b633af3a..2d5e11e3 100644
--- a/package.json
+++ b/package.json
@@ -102,7 +102,7 @@
     "nock": "^13.5.6",
     "prettier": "^3.8.3",
     "ts-jest": "^29.4.9",
-    "typescript": "^5.9.3",
+    "typescript": "^6.0.3",
     "typescript-eslint": "^8.58.2",
     "undici": "^7.24.4"
   }
diff --git a/tsconfig.json b/tsconfig.json
index 679afac9..23a9fb51 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -6,7 +6,6 @@
     "rootDir": "./src",
     "moduleResolution": "Bundler",
     "isolatedModules": true,
-    "baseUrl": "./",
     "sourceMap": true,
     "outDir": "./dist",
     "noImplicitAny": true,
@@ -14,6 +13,7 @@
     "forceConsistentCasingInFileNames": true,
     "strict": true,
     "skipLibCheck": true,
+    "ignoreDeprecations": "6.0",
     "newLine": "lf"
   },
   "exclude": ["./dist", "./node_modules", "./__tests__", "./coverage"]
diff --git a/tsconfig.lint.json b/tsconfig.lint.json
index a08b5639..09b3baa8 100644
--- a/tsconfig.lint.json
+++ b/tsconfig.lint.json
@@ -1,8 +1,9 @@
 {
-  "$schema": "https://json.schemastore.org/tsconfig",
   "extends": "./tsconfig.json",
   "compilerOptions": {
-    "noEmit": true
+    "rootDir": ".",
+    "noEmit": true,
+    "types": ["jest", "node"]
   },
   "include": ["./__tests__/**/*", "./src/**/*"],
   "exclude": ["./dist", "./node_modules", "./coverage", "*.json"]