diff --git a/tests/src/Functional/FillPdfFormFormTest.php b/tests/src/Functional/FillPdfFormFormTest.php
index b9f4deef80a98b9766d82a3c5c075438d9d196d0..13531cb0812c01a6772182fb8a6385fe62db4d84 100644
--- a/tests/src/Functional/FillPdfFormFormTest.php
+++ b/tests/src/Functional/FillPdfFormFormTest.php
@@ -88,6 +88,42 @@ class FillPdfFormFormTest extends FillPdfUploadTestBase {
     }
   }
 
+  /**
+   * Test uploading an updated PDF.
+   *
+   * It should also test for "These keys couldn't be found in the new PDF:" and
+   * the list of missing keys, when the keys are different. However, in testing,
+   * it does not actually parse the PDF, so the keys are never different. A fake
+   * list of fields is in TestPdfBackend::getParseResult();
+   */
+  public function testFormFormUploadUpdate() {
+    // Upload the initial PDF.
+    $this->drupalGet('admin/structure/fillpdf');
+    $this->assertSession()->statusCodeEquals(200);
+    $edit = [
+      'files[upload_pdf]' => $this->getTestPdfPath('fillpdf_test_v3.pdf'),
+    ];
+    $this->submitForm($edit, self::OP_CREATE);
+    $this->assertSession()->statusCodeEquals(200);
+
+    // Upload the updated PDF.
+    $edit = [
+      'files[upload_pdf]' => $this->getTestPdfPath('fillpdf_test_v3.pdf'),
+    ];
+    $this->submitForm($edit, self::OP_SAVE);
+    $this->assertSession()->statusCodeEquals(200);
+
+    // Status messages.
+    $messages = [
+      'FillPDF Form has been updated.',
+      'Your previous field mappings have been transferred to the new PDF template you uploaded.',
+      'You might also want to update the Filename pattern field; this has not been changed.',
+    ];
+    foreach ($messages as $message) {
+      $this->assertSession()->elementExists('xpath', '//div[@aria-label="Status message"]/ul/li[contains(normalize-space(), "' . $message . '")]');
+    }
+  }
+
   /**
    * Tests the FillPdfForm entity's edit form.
    */