diff --git a/eslint.config.mjs b/eslint.config.mjs
index dcf8d90..017a0c9 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -13,6 +13,15 @@ export default createConfigForNuxt({
     stylistic: true,
   },
 })
+  .append({
+    files: ['packages/**/src/**'],
+    rules: {
+      'import/extensions': [
+        'error',
+        'ignorePackages',
+      ],
+    },
+  })
   .append(
     ...svelte.configs.recommended,
   )
diff --git a/packages/comark-html/src/index.ts b/packages/comark-html/src/index.ts
index 3ac7441..d34f3e6 100644
--- a/packages/comark-html/src/index.ts
+++ b/packages/comark-html/src/index.ts
@@ -1,8 +1,8 @@
 import type { ParseOptions, RenderOptions } from 'comark'
 import { createParse } from 'comark'
-import { renderHTML } from './render'
+import { renderHTML } from './render.ts'
 
-export { renderHTML } from './render'
+export { renderHTML } from './render.ts'
 
 /**
  * Creates a reusable parse+render function with pre-configured options.
diff --git a/packages/comark-react/src/components/Comark.tsx b/packages/comark-react/src/components/Comark.tsx
index 5c03600..eb1d3f3 100644
--- a/packages/comark-react/src/components/Comark.tsx
+++ b/packages/comark-react/src/components/Comark.tsx
@@ -1,8 +1,8 @@
 import React from 'react'
 import { parse } from 'comark'
 import type { ParseOptions } from 'comark'
-import { ComarkRenderer } from './ComarkRenderer'
-import { ComarkClient } from './ComarkClient'
+import { ComarkRenderer } from './ComarkRenderer.tsx'
+import { ComarkClient } from './ComarkClient.tsx'
 
 export interface ComarkProps {
   /**
diff --git a/packages/comark-react/src/components/ComarkClient.tsx b/packages/comark-react/src/components/ComarkClient.tsx
index 59bb095..c7330cf 100644
--- a/packages/comark-react/src/components/ComarkClient.tsx
+++ b/packages/comark-react/src/components/ComarkClient.tsx
@@ -3,7 +3,7 @@
 import { use, useDeferredValue, useMemo, Suspense } from 'react'
 import { parse } from 'comark'
 import type { ComarkTree } from 'comark'
-import { ComarkRenderer } from './ComarkRenderer'
+import { ComarkRenderer } from './ComarkRenderer.tsx'
 import type { ComarkProps } from './Comark'
 
 interface ComarkContentProps extends Omit<ComarkProps, 'markdown' | 'children' | 'options' | 'plugins'> {
diff --git a/packages/comark-react/src/components/ComarkRenderer.tsx b/packages/comark-react/src/components/ComarkRenderer.tsx
index 66f0618..891885c 100644
--- a/packages/comark-react/src/components/ComarkRenderer.tsx
+++ b/packages/comark-react/src/components/ComarkRenderer.tsx
@@ -1,7 +1,7 @@
 import type { ComarkElement, ComarkNode, ComarkTree, ComponentManifest, NodeRenderData } from 'comark'
 import React, { lazy, Suspense, useMemo } from 'react'
 import { pascalCase, camelCase, resolveAttributes } from 'comark/utils'
-import { findLastTextNodeAndAppendNode, getCaret } from '../utils/caret'
+import { findLastTextNodeAndAppendNode, getCaret } from '../utils/caret.ts'
 
 /**
  * Helper to get tag from a ComarkNode
diff --git a/packages/comark-react/src/index.ts b/packages/comark-react/src/index.ts
index b905646..aab2e0f 100644
--- a/packages/comark-react/src/index.ts
+++ b/packages/comark-react/src/index.ts
@@ -1,12 +1,12 @@
 import React from 'react'
-import { Comark } from './components/Comark'
-import { ComarkRenderer } from './components/ComarkRenderer'
+import { Comark } from './components/Comark.tsx'
+import { ComarkRenderer } from './components/ComarkRenderer.tsx'
 import type { ComarkProps } from './components/Comark'
 import type { ComarkRendererProps } from './components/ComarkRenderer'
 import type { ParseOptions } from 'comark'
 
-export { ComarkRenderer } from './components/ComarkRenderer'
-export { ComarkClient } from './components/ComarkClient'
+export { ComarkRenderer } from './components/ComarkRenderer.tsx'
+export { ComarkClient } from './components/ComarkClient.tsx'
 export { Comark }
 export type * from 'comark'
 
diff --git a/packages/comark-react/src/plugins/binding.ts b/packages/comark-react/src/plugins/binding.ts
index be554a5..b686836 100644
--- a/packages/comark-react/src/plugins/binding.ts
+++ b/packages/comark-react/src/plugins/binding.ts
@@ -1,4 +1,4 @@
 export * from 'comark/plugins/binding'
 export { default } from 'comark/plugins/binding'
 
-export { Binding } from '../components/Binding'
+export { Binding } from '../components/Binding.tsx'
diff --git a/packages/comark-react/src/plugins/math.ts b/packages/comark-react/src/plugins/math.ts
index e8e670d..edbe403 100644
--- a/packages/comark-react/src/plugins/math.ts
+++ b/packages/comark-react/src/plugins/math.ts
@@ -1,4 +1,4 @@
 export * from 'comark/plugins/math'
 export { default } from 'comark/plugins/math'
 
-export { Math } from '../components/Math'
+export { Math } from '../components/Math.tsx'
diff --git a/packages/comark-react/src/plugins/mermaid.ts b/packages/comark-react/src/plugins/mermaid.ts
index 1f7252a..9648d34 100644
--- a/packages/comark-react/src/plugins/mermaid.ts
+++ b/packages/comark-react/src/plugins/mermaid.ts
@@ -1,4 +1,4 @@
 export * from 'comark/plugins/mermaid'
 export { default } from 'comark/plugins/mermaid'
 
-export { Mermaid } from '../components/Mermaid'
+export { Mermaid } from '../components/Mermaid.tsx'
diff --git a/packages/comark/src/internal/stringify/handlers/code.ts b/packages/comark/src/internal/stringify/handlers/code.ts
index 42e4110..a2253f3 100644
--- a/packages/comark/src/internal/stringify/handlers/code.ts
+++ b/packages/comark/src/internal/stringify/handlers/code.ts
@@ -1,7 +1,7 @@
 import type { State } from 'comark/render'
 import type { ComarkElement } from 'comark'
 import { comarkAttributes } from '../attributes.ts'
-import { textContent } from 'comark/utils'
+import { textContent } from '../../../utils/index.ts'
 
 export function code(node: ComarkElement, _state: State) {
   const [_, attrs] = node
diff --git a/packages/comark/src/internal/stringify/handlers/del.ts b/packages/comark/src/internal/stringify/handlers/del.ts
index d7ba0b1..e5a5f3a 100644
--- a/packages/comark/src/internal/stringify/handlers/del.ts
+++ b/packages/comark/src/internal/stringify/handlers/del.ts
@@ -1,6 +1,6 @@
 import type { State } from 'comark/render'
 import type { ComarkElement } from 'comark'
-import { textContent } from 'comark/utils'
+import { textContent } from '../../../utils/index.ts'
 
 export function del(node: ComarkElement, _: State) {
   return `~~${textContent(node)}~~`
diff --git a/packages/comark/src/internal/stringify/handlers/math.ts b/packages/comark/src/internal/stringify/handlers/math.ts
index 418714e..37ed604 100644
--- a/packages/comark/src/internal/stringify/handlers/math.ts
+++ b/packages/comark/src/internal/stringify/handlers/math.ts
@@ -1,6 +1,6 @@
 import type { State } from 'comark/render'
 import type { ComarkElement } from 'comark'
-import { textContent } from 'comark/utils'
+import { textContent } from '../../../utils/index.ts'
 
 export function math(node: ComarkElement, state: State, parent?: ComarkElement) {
   const content = textContent(node)
diff --git a/packages/comark/src/internal/stringify/handlers/pre.ts b/packages/comark/src/internal/stringify/handlers/pre.ts
index 5c74d1f..0c3ba77 100644
--- a/packages/comark/src/internal/stringify/handlers/pre.ts
+++ b/packages/comark/src/internal/stringify/handlers/pre.ts
@@ -1,6 +1,6 @@
 import type { State } from 'comark/render'
 import type { ComarkElement } from 'comark'
-import { textContent } from 'comark/utils'
+import { textContent } from '../../../utils/index.ts'
 
 export function pre(node: ComarkElement, state: State) {
   const [_, attributes, ...children] = node
diff --git a/packages/comark/src/plugins/alert.ts b/packages/comark/src/plugins/alert.ts
index d1ad39f..3a884f0 100644
--- a/packages/comark/src/plugins/alert.ts
+++ b/packages/comark/src/plugins/alert.ts
@@ -1,5 +1,5 @@
 import type { ComarkElement } from 'comark'
-import { visit } from 'comark/utils'
+import { visit } from '../utils/index.ts'
 import { defineComarkPlugin } from '../utils/helpers.ts'
 
 interface Marker {
diff --git a/packages/comark/src/plugins/binding.ts b/packages/comark/src/plugins/binding.ts
index a63ac92..e924bde 100644
--- a/packages/comark/src/plugins/binding.ts
+++ b/packages/comark/src/plugins/binding.ts
@@ -1,5 +1,5 @@
 import type { PluginWithOptions, MarkdownExit } from 'markdown-exit'
-import { defineComarkPlugin } from '../utils/helpers'
+import { defineComarkPlugin } from '../utils/helpers.ts'
 import type { MarkdownItPlugin, NodeHandler } from '../types'
 
 export interface MdcInlineBindingOptions {
diff --git a/packages/comark/src/plugins/breaks.ts b/packages/comark/src/plugins/breaks.ts
index ce2e743..9cbcaae 100644
--- a/packages/comark/src/plugins/breaks.ts
+++ b/packages/comark/src/plugins/breaks.ts
@@ -1,5 +1,5 @@
 import { defineComarkPlugin } from '../utils/helpers.ts'
-import { visit } from 'comark/utils'
+import { visit } from '../utils/index.ts'
 
 export default defineComarkPlugin(() => ({
   name: 'breaks',
diff --git a/packages/comark/src/plugins/json-render.ts b/packages/comark/src/plugins/json-render.ts
index 3abd229..a6ae8d0 100644
--- a/packages/comark/src/plugins/json-render.ts
+++ b/packages/comark/src/plugins/json-render.ts
@@ -1,8 +1,8 @@
 import type { Spec, UIElement } from '@json-render/core'
 import type { ComarkElementAttributes, ComarkNode } from '../types'
-import { defineComarkPlugin } from '../parse'
-import { textContent, visit } from '../utils'
-import { parseYaml } from '../internal/yaml'
+import { defineComarkPlugin } from '../parse.ts'
+import { textContent, visit } from '../utils/index.ts'
+import { parseYaml } from '../internal/yaml.ts'
 
 function jsonRenderToAst(jrt: Spec | UIElement) {
   if (!(jrt as Spec).root) {
diff --git a/packages/comark/src/plugins/security.ts b/packages/comark/src/plugins/security.ts
index 1a2ffb6..56d6bd9 100644
--- a/packages/comark/src/plugins/security.ts
+++ b/packages/comark/src/plugins/security.ts
@@ -1,6 +1,6 @@
 import type { ComarkElement } from 'comark'
 import { defineComarkPlugin } from '../utils/helpers.ts'
-import { visit } from 'comark/utils'
+import { visit } from '../utils/index.ts'
 import { validateProps } from '../internal/props-validation.ts'
 import type { PropsValidationOptions } from '../internal/props-validation.ts'
 
diff --git a/packages/comark/tsconfig.json b/packages/comark/tsconfig.json
index c04a149..0ff233a 100644
--- a/packages/comark/tsconfig.json
+++ b/packages/comark/tsconfig.json
@@ -13,8 +13,8 @@
     "allowImportingTsExtensions": true,
     "rewriteRelativeImportExtensions": true,
     "declaration": true,
-    "rootDir": "./src"
+    "rootDir": "./src",
   },
   "include": ["src/**/*"],
-  "exclude": ["node_modules", "dist"]
+  "exclude": ["node_modules", "dist"],
 }