diff --git a/package-lock.json b/package-lock.json
index 414c9325..d42a16d3 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17,14 +17,13 @@
         "axios-retry": "^4.5.0",
         "flat": "^6.0.1",
         "https-proxy-agent": "^9.0.0",
-        "js-yaml": "^4.2.0",
+        "js-yaml": "^5.2.0",
         "markup-js": "^1.5.21"
       },
       "devDependencies": {
         "@biomejs/biome": "^2.5.1",
         "@changesets/cli": "^2.31.0",
         "@types/flat": "^5.0.5",
-        "@types/js-yaml": "^4.0.9",
         "@types/markup-js": "^1.5.0",
         "@types/node": "^24.13.2",
         "@types/sinon": "^21.0.0",
@@ -464,6 +463,29 @@
         "js-yaml": "^4.1.1"
       }
     },
+    "node_modules/@changesets/parse/node_modules/js-yaml": {
+      "version": "4.3.0",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.3.0.tgz",
+      "integrity": "sha512-1td788aAnnZ5qs7V2QIRl1owjtYpbKt749Y3xauqQgwIIGF/xXWz1wMTEBx5O3LK3lXLVuqXPdPxj2BoFHaW9Q==",
+      "dev": true,
+      "funding": [
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/puzrin"
+        },
+        {
+          "type": "github",
+          "url": "https://github.com/sponsors/nodeca"
+        }
+      ],
+      "license": "MIT",
+      "dependencies": {
+        "argparse": "^2.0.1"
+      },
+      "bin": {
+        "js-yaml": "bin/js-yaml.js"
+      }
+    },
     "node_modules/@changesets/pre": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/@changesets/pre/-/pre-2.0.2.tgz",
@@ -878,13 +900,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/@types/js-yaml": {
-      "version": "4.0.9",
-      "resolved": "https://registry.npmjs.org/@types/js-yaml/-/js-yaml-4.0.9.tgz",
-      "integrity": "sha512-k4MGaQl5TGo/iipqb2UDG2UwjXziSWkh0uysQelTlJpX1qGlpUZYm8PnO4DxG1qBomtJUdYJ6qR6xdIah10JLg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/@types/markup-js": {
       "version": "1.5.0",
       "resolved": "https://registry.npmjs.org/@types/markup-js/-/markup-js-1.5.0.tgz",
@@ -1693,9 +1708,9 @@
       "license": "ISC"
     },
     "node_modules/js-yaml": {
-      "version": "4.2.0",
-      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-4.2.0.tgz",
-      "integrity": "sha512-ePWsvanv0DWuDRsW8dnt+R4jQ31SCRCQ7hhNcPXZPsoBZiemuZNYGf7adZdqX2D86j6rvKp3RpCxVTSb8WQlOw==",
+      "version": "5.2.0",
+      "resolved": "https://registry.npmjs.org/js-yaml/-/js-yaml-5.2.0.tgz",
+      "integrity": "sha512-YeLUMlvR4Ou1B119LIaM0r65JvbOBooJDc9yEu0dClb/uSC5P4FrLU8OCCz/HXWvtPoIrR0dRzABTjo1sTN9Bw==",
       "funding": [
         {
           "type": "github",
@@ -1711,7 +1726,7 @@
         "argparse": "^2.0.1"
       },
       "bin": {
-        "js-yaml": "bin/js-yaml.js"
+        "js-yaml": "bin/js-yaml.mjs"
       }
     },
     "node_modules/jsonfile": {
diff --git a/package.json b/package.json
index 1faca836..da6dc4db 100644
--- a/package.json
+++ b/package.json
@@ -50,14 +50,13 @@
     "axios-retry": "^4.5.0",
     "flat": "^6.0.1",
     "https-proxy-agent": "^9.0.0",
-    "js-yaml": "^4.2.0",
+    "js-yaml": "^5.2.0",
     "markup-js": "^1.5.21"
   },
   "devDependencies": {
     "@biomejs/biome": "^2.5.1",
     "@changesets/cli": "^2.31.0",
     "@types/flat": "^5.0.5",
-    "@types/js-yaml": "^4.0.9",
     "@types/markup-js": "^1.5.0",
     "@types/node": "^24.13.2",
     "@types/sinon": "^21.0.0",
diff --git a/src/content.js b/src/content.js
index 07377312..5519d6d2 100644
--- a/src/content.js
+++ b/src/content.js
@@ -2,7 +2,7 @@ import fs from "node:fs";
 import path from "node:path";
 import * as github from "@actions/github";
 import { flatten } from "flat";
-import yaml from "js-yaml";
+import { JSON_SCHEMA, load } from "js-yaml";
 import markup from "markup-js";
 import Config from "./config.js";
 import SlackError from "./errors.js";
@@ -67,8 +67,8 @@ export default class Content {
     }
     try {
       const content = /** @type {Content} */ (
-        yaml.load(config.inputs.payload, {
-          schema: yaml.JSON_SCHEMA,
+        load(config.inputs.payload, {
+          schema: JSON_SCHEMA,
         })
       );
       return /** @type {Content} */ (content);
@@ -125,10 +125,10 @@ export default class Content {
         config.inputs.payloadFilePath.endsWith("yaml") ||
         config.inputs.payloadFilePath.endsWith("yml")
       ) {
-        const load = yaml.load(input, {
-          schema: yaml.JSON_SCHEMA,
+        const content = load(input, {
+          schema: JSON_SCHEMA,
         });
-        return /** @type {Content} */ (load);
+        return /** @type {Content} */ (content);
       }
       if (config.inputs.payloadFilePath.endsWith("json")) {
         return JSON.parse(input);