diff --git a/src/Form/FillPdfFormForm.php b/src/Form/FillPdfFormForm.php
index 92b9532..a23344f 100644
--- a/src/Form/FillPdfFormForm.php
+++ b/src/Form/FillPdfFormForm.php
@@ -123,8 +123,9 @@ class FillPdfFormForm extends ContentEntityForm {
       ],
       'upload_pdf' => [
         '#type' => 'file',
-        '#title' => 'Update PDF template',
-        '#description' => $this->t('Update the PDF template used by this form'),
+        '#title' => $this->t('Update PDF template'),
+        '#attributes' => ['accept' => 'application/pdf'],
+        '#description' => $this->t('Update the PDF file used as template by this form.'),
         '#weight' => $pdf_info_weight++,
       ],
       'sample_populate' => [
diff --git a/src/Form/FillPdfOverviewForm.php b/src/Form/FillPdfOverviewForm.php
index d5a9fb2..f9aeaa6 100644
--- a/src/Form/FillPdfOverviewForm.php
+++ b/src/Form/FillPdfOverviewForm.php
@@ -76,15 +76,7 @@ class FillPdfOverviewForm extends FillPdfAdminFormBase {
   }
 
   /**
-   * Form constructor.
-   *
-   * @param array $form
-   *   An associative array containing the structure of the form.
-   * @param \Drupal\Core\Form\FormStateInterface $form_state
-   *   The current state of the form.
-   *
-   * @return array
-   *   The form structure.
+   * @inheritdoc
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
     // @todo: convert to OOP
@@ -97,8 +89,9 @@ class FillPdfOverviewForm extends FillPdfAdminFormBase {
       if ($config->get('backend') !== 'fillpdf_service' || $this->moduleHandler->moduleExists('xmlrpc')) {
         $form['upload_pdf'] = [
           '#type' => 'file',
-          '#title' => 'Upload',
-          '#description' => $this->t('Upload a PDF template to create a new form'),
+          '#title' => $this->t('Upload PDF template'),
+          '#attributes' => ['accept' => 'application/pdf'],
+          '#description' => $this->t('Upload a fillable PDF file to create a new form.'),
         ];
 
         $form['submit'] = [
diff --git a/tests/src/Functional/AdminIdTest.php b/tests/src/Functional/AdminIdTest.php
index 55cb511..2a23027 100644
--- a/tests/src/Functional/AdminIdTest.php
+++ b/tests/src/Functional/AdminIdTest.php
@@ -18,6 +18,9 @@ class AdminIdTest extends BrowserTestBase {
   static public $modules = ['fillpdf_test'];
   protected $profile = 'minimal';
 
+  /**
+   * @inheritdoc
+   */
   protected function setUp() {
     parent::setUp();
 
@@ -29,6 +32,12 @@ class AdminIdTest extends BrowserTestBase {
    * Tests the overview form's PDF file upload functionality.
    */
   public function testOverviewFormUpload() {
+    $this->drupalGet('admin/structure/fillpdf');
+
+    // Check if on the overview form's upload widget, the 'accept' attribute is
+    // correctly set.
+    $this->assertSession()->elementAttributeContains('css', '#edit-upload-pdf', 'accept', 'application/pdf');
+
     // Without a PDF file being supplied, no FillPdf form should be created.
     $this->uploadTestPdf(NULL);
     $this->assertSession()->pageTextNotContains('New FillPDF form has been created.');
@@ -38,13 +47,22 @@ class AdminIdTest extends BrowserTestBase {
     $this->assertSession()->pageTextContains('New FillPDF form has been created.');
   }
 
+  /**
+   * Tests the overview form's edit links.
+   */
   public function testEditLink() {
     $this->uploadTestPdf('fillpdf_test_v3.pdf');
+
     $latest_fid = $this->getLatestFillPdfForm();
     $latest_fillpdf_form = FillPdfForm::load($latest_fid);
     $max_fid_after = $latest_fillpdf_form->fid->value;
     $this->drupalGet('admin/structure/fillpdf/' . $max_fid_after);
     $this->assertSession()->statusCodeEquals(200);
+
+    // Check if on the entity form's upload widget, the 'accept' attribute is
+    // correctly set.
+    // @todo This test doesn't belong here.
+    $this->assertSession()->elementAttributeContains('css', '#edit-upload-pdf', 'accept', 'application/pdf');
   }
 
 }