diff --git a/bun.lock b/bun.lock
index 1179f64..15e58fd 100644
--- a/bun.lock
+++ b/bun.lock
@@ -25,6 +25,7 @@
         "@lexical/headless": "0.42.0",
         "@tailwindcss/vite": "^4.2.2",
         "@types/node": "^25.5.0",
+        "@types/prismjs": "^1.26.6",
         "@types/react": "^19.2.14",
         "@types/react-dom": "^19.2.3",
         "@vitejs/plugin-react": "5.1.0",
@@ -338,6 +339,8 @@
 
     "@types/node": ["@types/node@25.5.0", "", { "dependencies": { "undici-types": "~7.18.0" } }, "sha512-jp2P3tQMSxWugkCUKLRPVUpGaL5MVFwF8RDuSRztfwgN1wmqJeMSbKlnEtQqU8UrhTmzEmZdu2I6v2dpp7XIxw=="],
 
+    "@types/prismjs": ["@types/prismjs@1.26.6", "", {}, "sha512-vqlvI7qlMvcCBbVe0AKAb4f97//Hy0EBTaiW8AalRnG/xAN5zOiWWyrNqNXeq8+KAuvRewjCVY1+IPxk4RdNYw=="],
+
     "@types/react": ["@types/react@19.2.14", "", { "dependencies": { "csstype": "^3.2.2" } }, "sha512-ilcTH/UniCkMdtexkoCN0bI7pMcJDvmQFPvuPvmEaYA/NSfFTAgdUSLAoVjaRJm7+6PvcM+q1zYOwS4wTYMF9w=="],
 
     "@types/react-dom": ["@types/react-dom@19.2.3", "", { "peerDependencies": { "@types/react": "^19.2.0" } }, "sha512-jp2L/eY6fn+KgVVQAOqYItbF0VY/YApe5Mz2F0aykSO8gx31bYCZyvSeYxCHKvzHG5eZjc+zyaS5BrBWya2+kQ=="],
diff --git a/package.json b/package.json
index c7e4f1c..14ca2a0 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,7 @@
     "@lexical/headless": "0.42.0",
     "@tailwindcss/vite": "^4.2.2",
     "@types/node": "^25.5.0",
+    "@types/prismjs": "^1.26.6",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "5.1.0",
diff --git a/src/renderer/components/MarkdownComposer.tsx b/src/renderer/components/MarkdownComposer.tsx
index e0d5ed0..f6add2b 100644
--- a/src/renderer/components/MarkdownComposer.tsx
+++ b/src/renderer/components/MarkdownComposer.tsx
@@ -20,7 +20,31 @@ import {
   $convertFromMarkdownString,
   $convertToMarkdownString,
 } from '@lexical/markdown';
-import { $isCodeNode, $createCodeNode, CodeNode, registerCodeHighlighting } from '@lexical/code';
+import { $isCodeNode, $createCodeNode, CodeNode } from '@lexical/code';
+
+// Prism must be on `globalThis` before @lexical/code-prism initializes its
+// tokenizer reference.  Vite's dev-mode esbuild CJS shim can race the global
+// assignment, so we force it here before importing the module.
+import Prism from 'prismjs';
+import 'prismjs/components/prism-clike';
+import 'prismjs/components/prism-javascript';
+import 'prismjs/components/prism-markup';
+import 'prismjs/components/prism-markdown';
+import 'prismjs/components/prism-c';
+import 'prismjs/components/prism-css';
+import 'prismjs/components/prism-objectivec';
+import 'prismjs/components/prism-sql';
+import 'prismjs/components/prism-python';
+import 'prismjs/components/prism-rust';
+import 'prismjs/components/prism-swift';
+import 'prismjs/components/prism-typescript';
+import 'prismjs/components/prism-java';
+import 'prismjs/components/prism-cpp';
+if (typeof globalThis !== 'undefined') {
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  (globalThis as any).Prism = Prism;
+}
+import { registerCodeHighlighting } from '@lexical/code-prism';
 import {
   $isListNode,
   INSERT_ORDERED_LIST_COMMAND,