diff --git a/README.md b/README.md
index a62a202..4b22924 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,9 @@ jobs:
           # Require all pull request statuses to be successful before
           # merging. Default is `false`.
           require_statuses_success: 'true'
+          # Label to apply to the pull request if the merge fails. Default is
+          # `automerge-fail`.
+          automerge_fail_label: 'merge-schedule-failed'
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 ```
diff --git a/action.yml b/action.yml
index e940993..eb7a92d 100644
--- a/action.yml
+++ b/action.yml
@@ -24,3 +24,9 @@ inputs:
       merging. Default is `false`.
     required: false
     default: 'false'
+  automerge_fail_label:
+    description: |-
+      Label to apply to the pull request if the merge fails. Default is
+      `automerge-fail`.
+    required: false
+    default: 'automerge-fail'
diff --git a/lib/comment.ts b/lib/comment.ts
index 7e77f58..b8edd66 100644
--- a/lib/comment.ts
+++ b/lib/comment.ts
@@ -5,10 +5,14 @@ type Octokit = InstanceType<typeof GitHub>;
 
 const commentHeader = "**Merge Schedule**";
 const commentFooter = "<!-- Merge Schedule Pull Request Comment -->";
+const commentFailFooter = "<!-- Merge Schedule Pull Request Comment Fail -->";
+
+type CommentVariant = "default" | "fail";
 
 export async function getPreviousComment(
   octokit: Octokit,
-  pullRequestNumber: number
+  pullRequestNumber: number,
+  variant: CommentVariant = "default"
 ) {
   const prComments = await octokit.paginate(
     octokit.rest.issues.listComments,
@@ -18,7 +22,9 @@ export async function getPreviousComment(
     },
     (response) => {
       return response.data.filter((comment) =>
-        comment.body?.includes(commentFooter)
+        comment.body?.includes(
+          variant === "fail" ? commentFailFooter : commentFooter
+        )
       );
     }
   );
@@ -35,13 +41,18 @@ const statePrefix: Record<State, string> = {
   pending: ":hourglass:",
 };
 
-export function generateBody(body: string, state: State) {
+export function generateBody(
+  body: string,
+  state: State,
+  variant: CommentVariant = "default"
+) {
   let newBody = body;
   if (!body.startsWith(commentHeader)) {
     newBody = `${commentHeader}\n${newBody}`;
   }
-  if (!body.endsWith(commentFooter)) {
-    newBody = `${newBody}\n${commentFooter}`;
+  const footer = variant === "fail" ? commentFailFooter : commentFooter;
+  if (!body.endsWith(footer)) {
+    newBody = `${newBody}\n${footer}`;
   }
   return `${statePrefix[state]} ${newBody}`;
 }
diff --git a/lib/environment.d.ts b/lib/environment.d.ts
index 9c08c55..ee936e8 100644
--- a/lib/environment.d.ts
+++ b/lib/environment.d.ts
@@ -7,6 +7,7 @@ declare global {
       INPUT_MERGE_METHOD: string;
       INPUT_TIME_ZONE: string;
       INPUT_REQUIRE_STATUSES_SUCCESS: string;
+      INPUT_AUTOMERGE_FAIL_LABEL: string;
     }
   }
 }
diff --git a/lib/handle-pull-request.test.ts b/lib/handle-pull-request.test.ts
index fde24ae..e0f01a8 100644
--- a/lib/handle-pull-request.test.ts
+++ b/lib/handle-pull-request.test.ts
@@ -98,7 +98,7 @@ describe("handlePullRequest", () => {
       ],
       [`Schedule date found: "bad-date"\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
     ]);
     expect(createComment.mock.calls).toHaveLength(1);
@@ -125,7 +125,7 @@ describe("handlePullRequest", () => {
       ],
       [`Schedule date found: "2022-06-08"\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
     ]);
     expect(createComment.mock.calls).toHaveLength(1);
@@ -153,7 +153,7 @@ describe("handlePullRequest", () => {
       ],
       [`Schedule date found: "2022-06-08"\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
     ]);
     expect(createComment.mock.calls).toHaveLength(1);
@@ -180,7 +180,7 @@ describe("handlePullRequest", () => {
       ],
       [`Schedule date found: "2022-06-12"\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
     ]);
     expect(createComment.mock.calls).toHaveLength(1);
@@ -208,7 +208,7 @@ describe("handlePullRequest", () => {
       ],
       [`Schedule date found: "2022-06-12"\n`],
       [
-        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-1\n`,
+        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/3#issuecomment-31\n`,
       ],
     ]);
     expect(updateComment.mock.calls).toHaveLength(1);
diff --git a/lib/handle-schedule.test.ts b/lib/handle-schedule.test.ts
index 38d3dd8..9cfaebc 100644
--- a/lib/handle-schedule.test.ts
+++ b/lib/handle-schedule.test.ts
@@ -33,19 +33,24 @@ describe("handleSchedule", () => {
 
     expect(mockStdout.mock.calls).toEqual([
       [`Loading open pull requests\n`],
-      [`4 scheduled pull requests found\n`],
-      [`3 due pull requests found\n`],
+      [`5 scheduled pull requests found\n`],
+      [`4 due pull requests found\n`],
       [`https://github.com/gr2m/merge-schedule-action/pull/2 merged\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
       [`https://github.com/gr2m/merge-schedule-action/pull/3 merged\n`],
       [
-        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-1\n`,
+        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/3#issuecomment-31\n`,
       ],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/13#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/13#issuecomment-132\n`,
       ],
+      [`Label added: "automerge-fail"\n`],
+      [
+        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/6#issuecomment-61\n`,
+      ],
+      [`Label added: "automerge-fail"\n`],
     ]);
     expect(createComment.mock.calls).toHaveLength(2);
     expect(createComment.mock.calls[0][2]).toMatchInlineSnapshot(`
@@ -56,14 +61,21 @@ describe("handleSchedule", () => {
     expect(createComment.mock.calls[1][2]).toMatchInlineSnapshot(`
       ":x: **Merge Schedule**
       Scheduled merge failed: Pull Request is not mergeable
-      <!-- Merge Schedule Pull Request Comment -->"
+      In order to let the automerge-automation try again, the label \\"automerge-fail\\" should be removed.
+      <!-- Merge Schedule Pull Request Comment Fail -->"
     `);
-    expect(updateComment.mock.calls).toHaveLength(1);
+    expect(updateComment.mock.calls).toHaveLength(2);
     expect(updateComment.mock.calls[0][2]).toMatchInlineSnapshot(`
       ":white_check_mark: **Merge Schedule**
       Scheduled on 2022-06-09 (UTC) successfully merged
       <!-- Merge Schedule Pull Request Comment -->"
     `);
+    expect(updateComment.mock.calls[1][2]).toMatchInlineSnapshot(`
+      ":x: **Merge Schedule**
+      Scheduled merge failed: Pull Request is not mergeable
+      In order to let the automerge-automation try again, the label \\"automerge-fail\\" should be removed.
+      <!-- Merge Schedule Pull Request Comment Fail -->"
+    `);
   });
 
   test("due pull requests with require_statuses_success = true", async () => {
@@ -76,18 +88,23 @@ describe("handleSchedule", () => {
 
     expect(mockStdout.mock.calls).toEqual([
       [`Loading open pull requests\n`],
-      [`4 scheduled pull requests found\n`],
-      [`3 due pull requests found\n`],
+      [`5 scheduled pull requests found\n`],
+      [`4 due pull requests found\n`],
       [`https://github.com/gr2m/merge-schedule-action/pull/2 merged\n`],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/2#issuecomment-22\n`,
       ],
       [
         `https://github.com/gr2m/merge-schedule-action/pull/3 is not ready to be merged yet because all checks are not completed or statuses are not success\n`,
       ],
       [
-        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/13#issuecomment-2\n`,
+        `Comment created: https://github.com/gr2m/merge-schedule-action/issues/13#issuecomment-132\n`,
       ],
+      [`Label added: "automerge-fail"\n`],
+      [
+        `Comment updated: https://github.com/gr2m/merge-schedule-action/issues/6#issuecomment-61\n`,
+      ],
+      [`Label added: "automerge-fail"\n`],
     ]);
     expect(createComment.mock.calls).toHaveLength(2);
     expect(createComment.mock.calls[0][2]).toMatchInlineSnapshot(`
@@ -98,8 +115,15 @@ describe("handleSchedule", () => {
     expect(createComment.mock.calls[1][2]).toMatchInlineSnapshot(`
       ":x: **Merge Schedule**
       Scheduled merge failed: Pull Request is not mergeable
-      <!-- Merge Schedule Pull Request Comment -->"
+      In order to let the automerge-automation try again, the label \\"automerge-fail\\" should be removed.
+      <!-- Merge Schedule Pull Request Comment Fail -->"
+    `);
+    expect(updateComment.mock.calls).toHaveLength(1);
+    expect(updateComment.mock.calls[0][2]).toMatchInlineSnapshot(`
+      ":x: **Merge Schedule**
+      Scheduled merge failed: Pull Request is not mergeable
+      In order to let the automerge-automation try again, the label \\"automerge-fail\\" should be removed.
+      <!-- Merge Schedule Pull Request Comment Fail -->"
     `);
-    expect(updateComment.mock.calls).toHaveLength(0);
   });
 });
diff --git a/lib/handle-schedule.ts b/lib/handle-schedule.ts
index cee2a48..eb1ef89 100644
--- a/lib/handle-schedule.ts
+++ b/lib/handle-schedule.ts
@@ -28,6 +28,7 @@ export default async function handleSchedule(): Promise<void> {
   const mergeMethod = process.env.INPUT_MERGE_METHOD;
   const requireStatusesSuccess =
     process.env.INPUT_REQUIRE_STATUSES_SUCCESS === "true";
+  const automergeFailLabel = process.env.INPUT_AUTOMERGE_FAIL_LABEL;
   if (!isValidMergeMethod(mergeMethod)) {
     core.setFailed(`merge_method "${mergeMethod}" is invalid`);
     return;
@@ -46,6 +47,9 @@ export default async function handleSchedule(): Promise<void> {
       return response.data
         .filter((pullRequest) => !isFork(pullRequest as SimplePullRequest))
         .filter((pullRequest) => hasScheduleCommand(pullRequest.body))
+        .filter((pullRequest) =>
+          pullRequest.labels.every((label) => label.name !== automergeFailLabel)
+        )
         .map((pullRequest) => {
           return {
             number: pullRequest.number,
@@ -95,15 +99,39 @@ export default async function handleSchedule(): Promise<void> {
       });
       core.info(`${pullRequest.html_url} merged`);
     } catch (error) {
-      const { data } = await createComment(
+      const previousComment = await getPreviousComment(
         octokit,
         pullRequest.number,
-        generateBody(
-          `Scheduled merge failed: ${(error as Error).message}`,
-          "error"
-        )
+        "fail"
       );
-      core.info(`Comment created: ${data.html_url}`);
+      const commentBody = generateBody(
+        `Scheduled merge failed: ${
+          (error as Error).message
+        }\nIn order to let the automerge-automation try again, the label "${automergeFailLabel}" should be removed.`,
+        "error",
+        "fail"
+      );
+      if (previousComment) {
+        const { data } = await updateComment(
+          octokit,
+          previousComment.id,
+          commentBody
+        );
+        core.info(`Comment updated: ${data.html_url}`);
+      } else {
+        const { data } = await createComment(
+          octokit,
+          pullRequest.number,
+          commentBody
+        );
+        core.info(`Comment created: ${data.html_url}`);
+      }
+      await octokit.rest.issues.addLabels({
+        ...github.context.repo,
+        issue_number: pullRequest.number,
+        labels: [automergeFailLabel],
+      });
+      core.info(`Label added: "${automergeFailLabel}"`);
       continue;
     }
 
diff --git a/test/mocks/github.ts b/test/mocks/github.ts
index 82c1a3c..ca5bff6 100644
--- a/test/mocks/github.ts
+++ b/test/mocks/github.ts
@@ -1,7 +1,5 @@
 import { rest } from "msw";
 
-const githubUrl = (path: string) => `https://api.github.com${path}`;
-
 type BasePathParams = {
   owner: string;
   repo: string;
@@ -23,27 +21,134 @@ type CommitStatusesPathParams = BasePathParams & {
   ref: string;
 };
 
+const githubUrl = (path: string) => `https://api.github.com${path}`;
+const owner = "gr2m";
+const repo = "merge-schedule-action";
+const githubPullRequestUrl = (id: number) =>
+  `https://github.com/${owner}/${repo}/pull/${id}`;
+const pullRequests = [
+  {
+    number: 2,
+    html_url: githubPullRequestUrl(2),
+    state: "open",
+    body: "Simple body\n/schedule 2022-06-08",
+    head: {
+      sha: "abc123success",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [],
+  },
+  {
+    number: 3,
+    html_url: githubPullRequestUrl(3),
+    state: "open",
+    body: "Simple body\n/schedule 2022-06-09",
+    head: {
+      sha: "abc123pending",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [],
+  },
+  {
+    number: 4,
+    html_url: githubPullRequestUrl(4),
+    state: "open",
+    body: "Simple body\n/schedule 2022-06-12",
+    head: {
+      sha: "abc123success",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [],
+  },
+  {
+    number: 13,
+    html_url: githubPullRequestUrl(13),
+    state: "open",
+    body: "With conflicts body\n/schedule 2022-06-09",
+    head: {
+      sha: "abc123success",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [],
+  },
+  {
+    number: 5,
+    html_url: githubPullRequestUrl(5),
+    state: "open",
+    body: "With automerge-fail label\n/schedule 2022-06-07",
+    head: {
+      sha: "abc123success",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [
+      {
+        name: "automerge-fail",
+      },
+    ],
+  },
+  {
+    number: 6,
+    html_url: githubPullRequestUrl(6),
+    state: "open",
+    body: "With automerge-fail previous comment\n/schedule 2022-06-07",
+    head: {
+      sha: "abc123success",
+      repo: {
+        fork: false,
+      },
+    },
+    labels: [],
+  },
+];
+const pullRequestComments = pullRequests.map((pullRequest) => {
+  let body = "";
+  switch (pullRequest.number) {
+    case 3:
+      body = "<!-- Merge Schedule Pull Request Comment -->";
+      break;
+    case 4:
+      body = `:hourglass: **Merge Schedule**\nScheduled to be merged on 2022-06-12 00:00:00 (UTC)\n<!-- Merge Schedule Pull Request Comment -->`;
+      break;
+    case 6:
+      body = `:x: **Merge Schedule**\nScheduled merge failed: Pull Request is not mergeable\nIn order to let the automerge-automation try again, the label \\"automerge-fail\\" should be removed.\n<!-- Merge Schedule Pull Request Comment Fail -->`;
+      break;
+    default:
+      body = "Sample comment";
+      break;
+  }
+  const id = parseInt(`${pullRequest.number}1`, 10);
+  return [
+    {
+      id,
+      html_url: `https://github.com/${owner}/${repo}/issues/${pullRequest.number}#issuecomment-${id}`,
+      body,
+    },
+  ];
+});
+
 export const githubHandlers = [
   // List pull request comments
   // https://docs.github.com/en/rest/issues/comments#list-issue-comments
   rest.get<{}, IssueCommentsPathParams>(
     githubUrl("/repos/:owner/:repo/issues/:issue_number/comments"),
     (req, res, ctx) => {
-      const { owner, repo, issue_number } = req.params;
+      const { issue_number } = req.params;
+      const pullRequestIndex = pullRequests.findIndex(
+        (item) => item.number === +issue_number
+      );
       return res(
         ctx.status(200),
-        ctx.json([
-          {
-            id: 1,
-            html_url: `https://github.com/${owner}/${repo}/issues/${issue_number}#issuecomment-1`,
-            body:
-              issue_number === "4"
-                ? `:hourglass: **Merge Schedule**\nScheduled to be merged on 2022-06-12 00:00:00 (UTC)\n<!-- Merge Schedule Pull Request Comment -->`
-                : issue_number === "3"
-                ? "<!-- Merge Schedule Pull Request Comment -->"
-                : "Sample comment",
-          },
-        ])
+        ctx.json(pullRequestComments[pullRequestIndex])
       );
     }
   ),
@@ -53,13 +158,14 @@ export const githubHandlers = [
   rest.post<{ body: string }, IssueCommentsPathParams>(
     githubUrl("/repos/:owner/:repo/issues/:issue_number/comments"),
     (req, res, ctx) => {
-      const { owner, repo, issue_number } = req.params;
+      const { issue_number } = req.params;
+      const id = parseInt(`${issue_number}2`, 10);
       return res(
         ctx.status(201),
         ctx.json({
-          id: 2,
-          html_url: `https://github.com/${owner}/${repo}/issues/${issue_number}#issuecomment-2`,
-          body: req.body.body || "",
+          id,
+          html_url: `https://github.com/${owner}/${repo}/issues/${issue_number}#issuecomment-${id}`,
+          body: req.body.body,
         })
       );
     }
@@ -70,14 +176,15 @@ export const githubHandlers = [
   rest.patch<{ body: string }, IssueCommentPathParams>(
     githubUrl("/repos/:owner/:repo/issues/comments/:comment_id"),
     (req, res, ctx) => {
-      const { owner, repo, comment_id } = req.params;
+      const { comment_id } = req.params;
       const id = parseInt(comment_id, 10);
+      const issueNumber = parseInt(comment_id.slice(0, -1), 10);
       return res(
         ctx.status(200),
         ctx.json({
           id,
-          html_url: `https://github.com/${owner}/${repo}/issues/2#issuecomment-${id}`,
-          body: req.body.body || "",
+          html_url: `https://github.com/${owner}/${repo}/issues/${issueNumber}#issuecomment-${id}`,
+          body: req.body.body,
         })
       );
     }
@@ -97,60 +204,7 @@ export const githubHandlers = [
   rest.get<{}, BasePathParams>(
     githubUrl("/repos/:owner/:repo/pulls"),
     (req, res, ctx) => {
-      const { owner, repo } = req.params;
-      return res(
-        ctx.status(200),
-        ctx.json([
-          {
-            number: 2,
-            html_url: `https://github.com/${owner}/${repo}/pull/2`,
-            state: "open",
-            body: "Simple body\n/schedule 2022-06-08",
-            head: {
-              sha: "abc123success",
-              repo: {
-                fork: false,
-              },
-            },
-          },
-          {
-            number: 3,
-            html_url: `https://github.com/${owner}/${repo}/pull/3`,
-            state: "open",
-            body: "Simple body\n/schedule 2022-06-09",
-            head: {
-              sha: "abc123pending",
-              repo: {
-                fork: false,
-              },
-            },
-          },
-          {
-            number: 4,
-            html_url: `https://github.com/${owner}/${repo}/pull/4`,
-            state: "open",
-            body: "Simple body\n/schedule 2022-06-12",
-            head: {
-              sha: "abc123success",
-              repo: {
-                fork: false,
-              },
-            },
-          },
-          {
-            number: 13,
-            html_url: `https://github.com/${owner}/${repo}/pull/13`,
-            state: "open",
-            body: "With conflicts body\n/schedule 2022-06-09",
-            head: {
-              sha: "abc123success",
-              repo: {
-                fork: false,
-              },
-            },
-          },
-        ])
-      );
+      return res(ctx.status(200), ctx.json(pullRequests));
     }
   ),
 
@@ -161,7 +215,7 @@ export const githubHandlers = [
     (req, res, ctx) => {
       const pullNumber = parseInt(req.params.pull_number, 10);
 
-      if (pullNumber === 13) {
+      if ([13, 6].includes(pullNumber)) {
         return res(
           ctx.status(405),
           ctx.json({
@@ -215,4 +269,26 @@ export const githubHandlers = [
       );
     }
   ),
+
+  // Add labels to an issue/pull request
+  // https://docs.github.com/en/rest/issues/labels#add-labels-to-an-issue
+  rest.post<{ labels: string[] }, BasePathParams>(
+    githubUrl("/repos/:owner/:repo/issues/:issue_number/labels"),
+    (req, res, ctx) => {
+      return res(
+        ctx.status(200),
+        ctx.json(
+          req.body.labels.map((label, index) => ({
+            id: index + 1,
+            node_id: `node-${index + 1}`,
+            url: `https://api.github.com/repos/${owner}/${repo}/labels/${label}`,
+            name: label,
+            description: null,
+            color: "000000",
+            default: false,
+          }))
+        )
+      );
+    }
+  ),
 ];
diff --git a/test/setup-test-env.ts b/test/setup-test-env.ts
index 2b4e120..172922e 100644
--- a/test/setup-test-env.ts
+++ b/test/setup-test-env.ts
@@ -6,6 +6,7 @@ process.env.GITHUB_REPOSITORY = "gr2m/merge-schedule-action";
 process.env.INPUT_MERGE_METHOD = "merge";
 process.env.INPUT_TIME_ZONE = "UTC";
 process.env.INPUT_REQUIRE_STATUSES_SUCCESS = "false";
+process.env.INPUT_AUTOMERGE_FAIL_LABEL = "automerge-fail";
 
 beforeAll(() => server.listen({ onUnhandledRequest: "error" }));