diff --git a/.github/workflows/clean-patches.yml b/.github/workflows/clean-patches.yml
new file mode 100644
index 000000000000..53023353bfca
--- /dev/null
+++ b/.github/workflows/clean-patches.yml
@@ -0,0 +1,37 @@
+name: Clean patches when issues/PR are closed
+
+on:
+  schedule:
+    - cron: '30 3 * * 3'
+  workflow_dispatch:
+jobs:
+  clean:
+    runs-on: ubuntu-18.04
+    steps:
+    - name: Checkout webref
+      uses: actions/checkout@master
+
+    - name: Setup node.js
+      uses: actions/setup-node@master
+      with:
+        node-version: 14.x
+
+    - name: Install dependencies
+      run: |
+        npm install @actions/core
+        npm install @octokit/rest
+
+    - name: Drop patches locally when related issues/PR are closed
+      run: node tools/clean-patches.js
+
+    - name: Create PR to drop patches from repo if needed
+      uses: peter-evans/create-pull-request@v3
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        title: Drop patches that are no longer needed
+        commit-message: "Drop patches that are no longer needed"
+        body: ${{ env.dropped_patches }}
+        assignees: tidoust, dontcallmedom
+        branch: clean-patches
+        branch-suffix: timestamp
diff --git a/package-lock.json b/package-lock.json
index 4d14eb197b4c..a296a39c189e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4,6 +4,12 @@
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
+    "@actions/core": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/@actions/core/-/core-1.3.0.tgz",
+      "integrity": "sha512-xxtX0Cwdhb8LcgatfJkokqT8KzPvcIbwL9xpLU09nOwBzaStbfm0dNncsP0M4us+EpoPdWy7vbzU5vSOH7K6pg==",
+      "dev": true
+    },
     "@jsdevtools/ez-spawn": {
       "version": "3.0.4",
       "resolved": "https://registry.npmjs.org/@jsdevtools/ez-spawn/-/ez-spawn-3.0.4.tgz",
diff --git a/package.json b/package.json
index dccf07e7c972..4cd12e0be9aa 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "node": ">=10"
   },
   "devDependencies": {
+    "@actions/core": "1.3.0",
     "@jsdevtools/npm-publish": "1.4.3",
     "@octokit/rest": "18.5.3",
     "@webref/css": "file:packages/css",
diff --git a/tools/clean-patches.js b/tools/clean-patches.js
new file mode 100644
index 000000000000..346a48f9def5
--- /dev/null
+++ b/tools/clean-patches.js
@@ -0,0 +1,134 @@
+/**
+ * Check GitHub issues and pull requests referenced by patches and create
+ * a pull request to drop patches that should no longer be needed.
+ */
+
+const core = require('@actions/core');
+const { Octokit } = require("@octokit/rest");
+const fs = require("fs");
+const path = require("path");
+
+
+/**
+ * Check GitHub issues and PR referenced by patch files and drop patch files
+ * that only reference closed issues and PR.
+ * 
+ * @function
+ * @return {String} A GitHub flavored markdown string that describes what
+ *   patches got dropped and why. To be used in a possible PR. Returns an
+ *   empty string when there are no patches to drop.
+ */
+async function dropPatchesWhenPossible() {
+  const rootDir = path.join(__dirname, "..", "ed");
+
+  console.log("Gather patch files");
+  let patches = [];
+  const subDirs = fs.readdirSync(rootDir);
+  for (const subDir of subDirs) {
+    if (subDir.endsWith("patches")) {
+      const files = fs.readdirSync(path.join(rootDir, subDir));
+      for (const file of files) {
+        if (file.endsWith(".patch")) {
+          const patch = path.join(subDir, file);
+          console.log(`- add "${patch}"`);
+          patches.push({ name: patch });
+        }
+      }
+    }
+  }
+
+  console.log();
+  console.log("Extract list of issues");
+  const diffStart = /^---$/m;
+  const issueUrl = /(?:^|\s)https:\/\/github\.com\/([^\/]+)\/([^\/]+)\/(issues|pull)\/(\d+)(?:\s|$)/g;
+  for (const patch of patches) {
+    const contents = fs.readFileSync(path.join(rootDir, patch.name), "utf8");
+    const desc = contents.substring(0, contents.match(diffStart)?.index);
+    const patchIssues = [...desc.matchAll(issueUrl)];
+    for (patchIssue of patchIssues) {
+      if (!patch.issues) {
+        patch.issues = [];
+      }
+      const issue = {
+        owner: patchIssue[1],
+        repo: patchIssue[2],
+        number: parseInt(patchIssue[4], 10),
+        url: `https://github.com/${patchIssue[1]}/${patchIssue[2]}/${patchIssue[3]}/${patchIssue[4]}`
+      }
+      console.log(`- "${patch.name}" linked to ${issue.url}`);
+      patch.issues.push(issue);
+    }
+
+    if (patchIssues.length === 0) {
+      console.log(`- "${patch.name}" not linked to any issue`);
+    }
+  }
+  patches = patches.filter(patch => patch.issues);
+
+  console.log();
+  console.log("Check status of GitHub issues/PR");
+  for (const patch of patches) {
+    for (const issue of patch.issues) {
+      const response = await octokit.issues.get({
+        owner: issue.owner,
+        repo: issue.repo,
+        issue_number: issue.number
+      });
+      issue.state = response?.data?.state ?? "unknown";
+      console.log(`- [${issue.state}] ${issue.url}`);
+    }
+  }
+
+  console.log();
+  console.log("Drop patches when possible");
+  patches = patches.filter(patch => patch.issues.every(issue => issue.state === "closed"));
+  if (patches.length > 0) {
+    const res = [];
+    for (const patch of patches) {
+      console.log(`- drop "${patch.name}"`);
+      fs.unlinkSync(path.join(rootDir, patch.name));
+      res.push(`- \`${patch.name}\` was linked to now closed: ` +
+        patch.issues.map(issue => `[${issue.owner}/${issue.repo}#${issue.number}](${issue.url})`).join(", "));
+    }
+    return res.join("\n");
+  }
+  else {
+    console.log("- No patch to drop at this time");
+    return "";
+  }
+}
+
+
+/*******************************************************************************
+Retrieve GH_TOKEN from environment, prepare Octokit and kick things off
+*******************************************************************************/
+const GH_TOKEN = (() => {
+  try {
+    return require("../config.json").GH_TOKEN;
+  } catch {
+    return process.env.GH_TOKEN;
+  }
+})();
+if (!GH_TOKEN) {
+  console.error("GH_TOKEN must be set to some personal access token as an env variable or in a config.json file");
+  process.exit(1);
+}
+
+const octokit = new Octokit({
+  auth: GH_TOKEN,
+  //log: console
+});
+
+
+dropPatchesWhenPossible()
+  .then(res => {
+    core.exportVariable("dropped_patches", res);
+    console.log();
+    console.log("Set dropped_variables env variable");
+    console.log(res);
+    console.log("== The end ==");
+  })
+  .catch(err => {
+    console.error(err);
+    process.exit(1);
+  });
\ No newline at end of file