diff --git a/package-lock.json b/package-lock.json
index 0dc1d3d..5a0f650 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,7 +10,7 @@
         "@github/markdownlint-github": "^0.6.3",
         "@webcomponents/custom-elements": "^1.6.0",
         "dom-input-range": "^1.1.5",
-        "markdownlint": "^0.33.0"
+        "markdownlint": "^0.34.0"
       },
       "devDependencies": {
         "@babel/core": "^7.21.8",
@@ -6052,28 +6052,28 @@
       }
     },
     "node_modules/markdown-it": {
-      "version": "14.0.0",
-      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.0.0.tgz",
-      "integrity": "sha512-seFjF0FIcPt4P9U39Bq1JYblX0KZCjDLFFQPHpL5AzHpqPEKtosxmdq/LTVZnjfH7tjt9BxStm+wXcDBNuYmzw==",
+      "version": "14.1.0",
+      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.1.0.tgz",
+      "integrity": "sha512-a54IwgWPaeBCAAsv13YgmALOF1elABB08FxO9i+r4VFk5Vl4pKokRPeX8u5TCgSsPi6ec1otfLjdOpVcgbpshg==",
       "dependencies": {
         "argparse": "^2.0.1",
         "entities": "^4.4.0",
         "linkify-it": "^5.0.0",
         "mdurl": "^2.0.0",
         "punycode.js": "^2.3.1",
-        "uc.micro": "^2.0.0"
+        "uc.micro": "^2.1.0"
       },
       "bin": {
         "markdown-it": "bin/markdown-it.mjs"
       }
     },
     "node_modules/markdownlint": {
-      "version": "0.33.0",
-      "resolved": "https://registry.npmjs.org/markdownlint/-/markdownlint-0.33.0.tgz",
-      "integrity": "sha512-4lbtT14A3m0LPX1WS/3d1m7Blg+ZwiLq36WvjQqFGsX3Gik99NV+VXp/PW3n+Q62xyPdbvGOCfjPqjW+/SKMig==",
+      "version": "0.34.0",
+      "resolved": "https://registry.npmjs.org/markdownlint/-/markdownlint-0.34.0.tgz",
+      "integrity": "sha512-qwGyuyKwjkEMOJ10XN6OTKNOVYvOIi35RNvDLNxTof5s8UmyGHlCdpngRHoRGNvQVGuxO3BJ7uNSgdeX166WXw==",
       "dependencies": {
-        "markdown-it": "14.0.0",
-        "markdownlint-micromark": "0.1.8"
+        "markdown-it": "14.1.0",
+        "markdownlint-micromark": "0.1.9"
       },
       "engines": {
         "node": ">=18"
@@ -6083,11 +6083,11 @@
       }
     },
     "node_modules/markdownlint-micromark": {
-      "version": "0.1.8",
-      "resolved": "https://registry.npmjs.org/markdownlint-micromark/-/markdownlint-micromark-0.1.8.tgz",
-      "integrity": "sha512-1ouYkMRo9/6gou9gObuMDnvZM8jC/ly3QCFQyoSPCS2XV1ZClU0xpKbL1Ar3bWWRT1RnBZkWUEiNKrI2CwiBQA==",
+      "version": "0.1.9",
+      "resolved": "https://registry.npmjs.org/markdownlint-micromark/-/markdownlint-micromark-0.1.9.tgz",
+      "integrity": "sha512-5hVs/DzAFa8XqYosbEAEg6ok6MF2smDj89ztn9pKkCtdKHVdPQuGMH7frFfYL9mLkvfFe4pTyAMffLbjf3/EyA==",
       "engines": {
-        "node": ">=16"
+        "node": ">=18"
       },
       "funding": {
         "url": "https://github.com/sponsors/DavidAnson"
@@ -8355,9 +8355,9 @@
       }
     },
     "node_modules/uc.micro": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.0.0.tgz",
-      "integrity": "sha512-DffL94LsNOccVn4hyfRe5rdKa273swqeA5DJpMOeFmEn1wCDc7nAbbB0gXlgBCL7TNzeTv6G7XVWzan7iJtfig=="
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.1.0.tgz",
+      "integrity": "sha512-ARDJmphmdvUk6Glw7y9DQ2bFkKBHwQHLi2lsaH6PPmz/Ka9sFOBsBluozhDltWmnv9u/cF6Rt87znRTPV+yp/A=="
     },
     "node_modules/unicode-canonical-property-names-ecmascript": {
       "version": "2.0.0",
@@ -13495,31 +13495,31 @@
       }
     },
     "markdown-it": {
-      "version": "14.0.0",
-      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.0.0.tgz",
-      "integrity": "sha512-seFjF0FIcPt4P9U39Bq1JYblX0KZCjDLFFQPHpL5AzHpqPEKtosxmdq/LTVZnjfH7tjt9BxStm+wXcDBNuYmzw==",
+      "version": "14.1.0",
+      "resolved": "https://registry.npmjs.org/markdown-it/-/markdown-it-14.1.0.tgz",
+      "integrity": "sha512-a54IwgWPaeBCAAsv13YgmALOF1elABB08FxO9i+r4VFk5Vl4pKokRPeX8u5TCgSsPi6ec1otfLjdOpVcgbpshg==",
       "requires": {
         "argparse": "^2.0.1",
         "entities": "^4.4.0",
         "linkify-it": "^5.0.0",
         "mdurl": "^2.0.0",
         "punycode.js": "^2.3.1",
-        "uc.micro": "^2.0.0"
+        "uc.micro": "^2.1.0"
       }
     },
     "markdownlint": {
-      "version": "0.33.0",
-      "resolved": "https://registry.npmjs.org/markdownlint/-/markdownlint-0.33.0.tgz",
-      "integrity": "sha512-4lbtT14A3m0LPX1WS/3d1m7Blg+ZwiLq36WvjQqFGsX3Gik99NV+VXp/PW3n+Q62xyPdbvGOCfjPqjW+/SKMig==",
+      "version": "0.34.0",
+      "resolved": "https://registry.npmjs.org/markdownlint/-/markdownlint-0.34.0.tgz",
+      "integrity": "sha512-qwGyuyKwjkEMOJ10XN6OTKNOVYvOIi35RNvDLNxTof5s8UmyGHlCdpngRHoRGNvQVGuxO3BJ7uNSgdeX166WXw==",
       "requires": {
-        "markdown-it": "14.0.0",
-        "markdownlint-micromark": "0.1.8"
+        "markdown-it": "14.1.0",
+        "markdownlint-micromark": "0.1.9"
       }
     },
     "markdownlint-micromark": {
-      "version": "0.1.8",
-      "resolved": "https://registry.npmjs.org/markdownlint-micromark/-/markdownlint-micromark-0.1.8.tgz",
-      "integrity": "sha512-1ouYkMRo9/6gou9gObuMDnvZM8jC/ly3QCFQyoSPCS2XV1ZClU0xpKbL1Ar3bWWRT1RnBZkWUEiNKrI2CwiBQA=="
+      "version": "0.1.9",
+      "resolved": "https://registry.npmjs.org/markdownlint-micromark/-/markdownlint-micromark-0.1.9.tgz",
+      "integrity": "sha512-5hVs/DzAFa8XqYosbEAEg6ok6MF2smDj89ztn9pKkCtdKHVdPQuGMH7frFfYL9mLkvfFe4pTyAMffLbjf3/EyA=="
     },
     "marky": {
       "version": "1.2.5",
@@ -15171,9 +15171,9 @@
       "dev": true
     },
     "uc.micro": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.0.0.tgz",
-      "integrity": "sha512-DffL94LsNOccVn4hyfRe5rdKa273swqeA5DJpMOeFmEn1wCDc7nAbbB0gXlgBCL7TNzeTv6G7XVWzan7iJtfig=="
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/uc.micro/-/uc.micro-2.1.0.tgz",
+      "integrity": "sha512-ARDJmphmdvUk6Glw7y9DQ2bFkKBHwQHLi2lsaH6PPmz/Ka9sFOBsBluozhDltWmnv9u/cF6Rt87znRTPV+yp/A=="
     },
     "unicode-canonical-property-names-ecmascript": {
       "version": "2.0.0",
diff --git a/package.json b/package.json
index f1a483b..f2b9dc1 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,7 @@
     "@github/markdownlint-github": "^0.6.3",
     "@webcomponents/custom-elements": "^1.6.0",
     "dom-input-range": "^1.1.5",
-    "markdownlint": "^0.33.0"
+    "markdownlint": "^0.34.0"
   },
   "devDependencies": {
     "@babel/core": "^7.21.8",
diff --git a/src/rules/start-heading-level.ts b/src/rules/start-heading-level.ts
index 408fc58..62c39fa 100644
--- a/src/rules/start-heading-level.ts
+++ b/src/rules/start-heading-level.ts
@@ -14,9 +14,10 @@ export default {
   names: ["start-heading-level"],
   description: "Initial heading level",
   tags: ["accessibility", "images"],
+  parser: "markdownit",
   function(params, onError) {
     const minLevel = getLevelConfig(params);
-    for (const token of params.tokens)
+    for (const token of params.parsers.markdownit.tokens)
       if (token.type === "heading_open") {
         const level = parseHTagLevel(token.tag);