diff --git a/__test__/input-helper.unit.test.ts b/__test__/input-helper.unit.test.ts
deleted file mode 100644
index 6355509..0000000
--- a/__test__/input-helper.unit.test.ts
+++ /dev/null
@@ -1,28 +0,0 @@
-import {getInputs} from '../src/input-helper'
-
-describe('input-helper tests', () => {
-  const ORIGINAL_ENV = process.env
-
-  beforeEach(() => {
-    jest.resetModules()
-    process.env = {...ORIGINAL_ENV}
-  })
-
-  afterAll(() => {
-    process.env = ORIGINAL_ENV
-  })
-
-  test('enableUrlCompletion should be false when "false" is passed', () => {
-    process.env['INPUT_ENABLE-URL-COMPLETION'] = 'false'
-
-    const inputs = getInputs()
-    expect(inputs.enableUrlCompletion).toBe(false)
-  })
-
-  test('enableUrlCompletion should be true when "true" is passed', () => {
-    process.env['INPUT_ENABLE-URL-COMPLETION'] = 'true'
-
-    const inputs = getInputs()
-    expect(inputs.enableUrlCompletion).toBe(true)
-  })
-})
diff --git a/action.yml b/action.yml
index 878d62e..9899483 100644
--- a/action.yml
+++ b/action.yml
@@ -22,7 +22,6 @@ inputs:
     description: >
       Enables completion of relative URLs to absolute ones
       Default: `false`
-    default: "false"
   image-extensions:
     description: >
       File extensions that will be treated as images
diff --git a/dist/index.js b/dist/index.js
index 5c93eb7..b66d398 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -128,7 +128,7 @@ function getInputs() {
         repository: core.getInput('repository'),
         shortDescription: core.getInput('short-description'),
         readmeFilepath: core.getInput('readme-filepath'),
-        enableUrlCompletion: core.getBooleanInput('enable-url-completion'),
+        enableUrlCompletion: Boolean(core.getInput('enable-url-completion')),
         imageExtensions: core.getInput('image-extensions')
     };
     // Environment variable input alternatives and their aliases
@@ -157,8 +157,7 @@ function getInputs() {
         inputs.readmeFilepath = process.env['README_FILEPATH'];
     }
     if (!inputs.enableUrlCompletion && process.env['ENABLE_URL_COMPLETION']) {
-        inputs.enableUrlCompletion =
-            process.env['ENABLE_URL_COMPLETION'].toLowerCase() === 'true';
+        inputs.enableUrlCompletion = Boolean(process.env['ENABLE_URL_COMPLETION']);
     }
     if (!inputs.imageExtensions && process.env['IMAGE_EXTENSIONS']) {
         inputs.imageExtensions = process.env['IMAGE_EXTENSIONS'];
@@ -167,6 +166,9 @@ function getInputs() {
     if (!inputs.readmeFilepath) {
         inputs.readmeFilepath = readmeHelper.README_FILEPATH_DEFAULT;
     }
+    if (!inputs.enableUrlCompletion) {
+        inputs.enableUrlCompletion = readmeHelper.ENABLE_URL_COMPLETION_DEFAULT;
+    }
     if (!inputs.imageExtensions) {
         inputs.imageExtensions = readmeHelper.IMAGE_EXTENSIONS_DEFAULT;
     }
@@ -311,12 +313,13 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
     });
 };
 Object.defineProperty(exports, "__esModule", ({ value: true }));
-exports.completeRelativeUrls = exports.getReadmeContent = exports.IMAGE_EXTENSIONS_DEFAULT = exports.README_FILEPATH_DEFAULT = void 0;
+exports.completeRelativeUrls = exports.getReadmeContent = exports.ENABLE_URL_COMPLETION_DEFAULT = exports.IMAGE_EXTENSIONS_DEFAULT = exports.README_FILEPATH_DEFAULT = void 0;
 const core = __importStar(__nccwpck_require__(7484));
 const fs = __importStar(__nccwpck_require__(9896));
 const utils = __importStar(__nccwpck_require__(9277));
 exports.README_FILEPATH_DEFAULT = './README.md';
 exports.IMAGE_EXTENSIONS_DEFAULT = 'bmp,gif,jpg,jpeg,png,svg,webp';
+exports.ENABLE_URL_COMPLETION_DEFAULT = false;
 const TITLE_REGEX = `(?: +"[^"]+")?`;
 const REPOSITORY_URL = `${process.env['GITHUB_SERVER_URL']}/${process.env['GITHUB_REPOSITORY']}`;
 const BLOB_PREFIX = `${REPOSITORY_URL}/blob/${process.env['GITHUB_REF_NAME']}/`;
diff --git a/src/input-helper.ts b/src/input-helper.ts
index 0f31920..7093ee3 100644
--- a/src/input-helper.ts
+++ b/src/input-helper.ts
@@ -18,7 +18,7 @@ export function getInputs(): Inputs {
     repository: core.getInput('repository'),
     shortDescription: core.getInput('short-description'),
     readmeFilepath: core.getInput('readme-filepath'),
-    enableUrlCompletion: core.getBooleanInput('enable-url-completion'),
+    enableUrlCompletion: Boolean(core.getInput('enable-url-completion')),
     imageExtensions: core.getInput('image-extensions')
   }
 
@@ -54,8 +54,7 @@ export function getInputs(): Inputs {
   }
 
   if (!inputs.enableUrlCompletion && process.env['ENABLE_URL_COMPLETION']) {
-    inputs.enableUrlCompletion =
-      process.env['ENABLE_URL_COMPLETION'].toLowerCase() === 'true'
+    inputs.enableUrlCompletion = Boolean(process.env['ENABLE_URL_COMPLETION'])
   }
 
   if (!inputs.imageExtensions && process.env['IMAGE_EXTENSIONS']) {
@@ -66,6 +65,9 @@ export function getInputs(): Inputs {
   if (!inputs.readmeFilepath) {
     inputs.readmeFilepath = readmeHelper.README_FILEPATH_DEFAULT
   }
+  if (!inputs.enableUrlCompletion) {
+    inputs.enableUrlCompletion = readmeHelper.ENABLE_URL_COMPLETION_DEFAULT
+  }
   if (!inputs.imageExtensions) {
     inputs.imageExtensions = readmeHelper.IMAGE_EXTENSIONS_DEFAULT
   }
diff --git a/src/readme-helper.ts b/src/readme-helper.ts
index f7e381e..90075c4 100644
--- a/src/readme-helper.ts
+++ b/src/readme-helper.ts
@@ -4,6 +4,7 @@ import * as utils from './utils'
 
 export const README_FILEPATH_DEFAULT = './README.md'
 export const IMAGE_EXTENSIONS_DEFAULT = 'bmp,gif,jpg,jpeg,png,svg,webp'
+export const ENABLE_URL_COMPLETION_DEFAULT = false
 
 const TITLE_REGEX = `(?: +"[^"]+")?`
 const REPOSITORY_URL = `${process.env['GITHUB_SERVER_URL']}/${process.env['GITHUB_REPOSITORY']}`