diff --git a/test/integration/jasmine-boot.js b/test/integration/jasmine-boot.js
index b6d904c84..5c74aa958 100644
--- a/test/integration/jasmine-boot.js
+++ b/test/integration/jasmine-boot.js
@@ -36,6 +36,7 @@ async function runTests(results) {
       "highlight_editor_spec.mjs",
       "ink_editor_spec.mjs",
       "scripting_spec.mjs",
+      "signature_editor_spec.mjs",
       "stamp_editor_spec.mjs",
       "text_field_spec.mjs",
       "text_layer_spec.mjs",
diff --git a/test/integration/signature_editor_spec.mjs b/test/integration/signature_editor_spec.mjs
new file mode 100644
index 000000000..60ac12c80
--- /dev/null
+++ b/test/integration/signature_editor_spec.mjs
@@ -0,0 +1,210 @@
+/* Copyright 2025 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import {
+  closePages,
+  getEditorSelector,
+  loadAndWait,
+  switchToEditor,
+  waitForTimeout,
+} from "./test_utils.mjs";
+
+const switchToSignature = switchToEditor.bind(null, "Signature");
+
+describe("Signature Editor", () => {
+  const descriptionInputSelector = "#addSignatureDescription > input";
+  const addButtonSelector = "#addSignatureAddButton";
+
+  describe("Basic operations", () => {
+    let pages;
+
+    beforeEach(async () => {
+      pages = await loadAndWait("empty.pdf", ".annotationEditorLayer");
+    });
+
+    afterEach(async () => {
+      await closePages(pages);
+    });
+
+    it("must check that the editor has been removed when the dialog is cancelled", async () => {
+      await Promise.all(
+        pages.map(async ([_, page]) => {
+          await switchToSignature(page);
+          await page.click("#editorSignatureAddSignature");
+
+          await page.waitForSelector("#addSignatureDialog", {
+            visible: true,
+          });
+
+          // An invisible editor is created but invisible.
+          const editorSelector = getEditorSelector(0);
+          await page.waitForSelector(editorSelector, { visible: false });
+
+          await page.click("#addSignatureCancelButton");
+
+          // The editor should have been removed.
+          await page.waitForSelector(`:not(${editorSelector})`);
+        })
+      );
+    });
+
+    it("must check that the basic and common elements are working as expected", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          await switchToSignature(page);
+          await page.click("#editorSignatureAddSignature");
+
+          await page.waitForSelector("#addSignatureDialog", {
+            visible: true,
+          });
+
+          await page.waitForSelector(
+            "#addSignatureTypeButton[aria-selected=true]"
+          );
+          await page.click("#addSignatureTypeInput");
+          await page.waitForSelector(
+            "#addSignatureSaveContainer[disabled=true]"
+          );
+          let description = await page.$eval(
+            descriptionInputSelector,
+            el => el.value
+          );
+          expect(description).withContext(browserName).toEqual("");
+          await page.waitForSelector(`${addButtonSelector}:disabled`);
+
+          await page.type("#addSignatureTypeInput", "PDF.js");
+          await page.waitForSelector(`${addButtonSelector}:not(:disabled)`);
+
+          // The save button should be enabled now.
+          await page.waitForSelector(
+            "#addSignatureSaveContainer:not([disabled])"
+          );
+          await page.waitForSelector("#addSignatureSaveCheckbox[checked=true]");
+
+          // The description has been filled in automatically.
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value !== ""`
+          );
+          description = await page.$eval(
+            descriptionInputSelector,
+            el => el.value
+          );
+          expect(description).withContext(browserName).toEqual("PDF.js");
+
+          // Clear the description.
+          await page.click("#addSignatureDescription > button");
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value === ""`
+          );
+
+          // Clear the text for the signature.
+          await page.click("#clearSignatureButton");
+          await page.waitForFunction(
+            `document.querySelector("#addSignatureTypeInput").value === ""`
+          );
+          // The save button should be disabled now.
+          await page.waitForSelector(
+            "#addSignatureSaveContainer[disabled=true]"
+          );
+          await page.waitForSelector(`${addButtonSelector}:disabled`);
+
+          await page.type("#addSignatureTypeInput", "PDF.js");
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value !== ""`
+          );
+
+          // Clearing the signature type should clear the description.
+          await page.click("#clearSignatureButton");
+          await page.waitForFunction(
+            `document.querySelector("#addSignatureTypeInput").value === ""`
+          );
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value === ""`
+          );
+
+          // Add a signature and change the description.
+          await page.type("#addSignatureTypeInput", "PDF.js");
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value !== ""`
+          );
+          await page.click("#addSignatureDescription > button");
+          await page.waitForFunction(
+            `document.querySelector("${descriptionInputSelector}").value === ""`
+          );
+          await page.type(descriptionInputSelector, "Hello World");
+          await page.type("#addSignatureTypeInput", "Hello");
+
+          // The description mustn't be changed.
+          // eslint-disable-next-line no-restricted-syntax
+          await waitForTimeout(100);
+          description = await page.$eval(
+            descriptionInputSelector,
+            el => el.value
+          );
+          expect(description).withContext(browserName).toEqual("Hello World");
+
+          await page.click("#addSignatureAddButton");
+          await page.waitForSelector("#addSignatureDialog", {
+            visible: false,
+          });
+
+          const editorSelector = getEditorSelector(0);
+          await page.waitForSelector(editorSelector, { visible: true });
+          await page.waitForSelector(
+            `.canvasWrapper > svg use[href="#path_p1_0"]`,
+            { visible: true }
+          );
+
+          // Check the tooltip.
+          await page.waitForSelector(
+            `.altText.editDescription[title="Hello World"]`
+          );
+
+          // Edit the description.
+          await page.click(`.altText.editDescription`);
+
+          await page.waitForSelector("#editSignatureDescriptionDialog", {
+            visible: true,
+          });
+          await page.waitForSelector("#editSignatureUpdateButton:disabled");
+          await page.waitForSelector(
+            `#editSignatureDescriptionDialog svg[aria-label="Hello World"]`
+          );
+          const editDescriptionInput = "#editSignatureDescription > input";
+          description = await page.$eval(editDescriptionInput, el => el.value);
+          expect(description).withContext(browserName).toEqual("Hello World");
+          await page.click("#editSignatureDescription > button");
+          await page.waitForFunction(
+            `document.querySelector("${editDescriptionInput}").value === ""`
+          );
+          await page.waitForSelector(
+            "#editSignatureUpdateButton:not(:disabled)"
+          );
+          await page.type(editDescriptionInput, "Hello PDF.js World");
+          await page.waitForSelector(
+            "#editSignatureUpdateButton:not(:disabled)"
+          );
+
+          await page.click("#editSignatureUpdateButton");
+
+          // Check the tooltip.
+          await page.waitForSelector(
+            `.altText.editDescription[title="Hello PDF.js World"]`
+          );
+        })
+      );
+    });
+  });
+});
diff --git a/web/signature_manager.js b/web/signature_manager.js
index f24f4099f..add12bc7f 100644
--- a/web/signature_manager.js
+++ b/web/signature_manager.js
@@ -946,6 +946,7 @@ class EditDescriptionDialog {
     clearDescription.addEventListener("click", () => {
       descriptionInput.value = "";
       clearDescription.disabled = true;
+      updateButton.disabled = this.#previousDescription === "";
     });
     descriptionInput.addEventListener(
       "input",