diff --git a/.eslintrc.js b/.eslintrc.js
index 007700b6dd7..44e8122ad3b 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -70,8 +70,6 @@ module.exports = {
         '@typescript-eslint/ban-types': 'off',
         '@typescript-eslint/comma-dangle': ['error', 'always-multiline'],
         '@typescript-eslint/explicit-module-boundary-types': 'off',
-        '@typescript-eslint/no-namespace': 'off',
-        'no-undef': 'off',
       },
     },
   ],
diff --git a/packages/core/src/CommandManager.ts b/packages/core/src/CommandManager.ts
index ceeecfc4f3f..b9fef148c03 100644
--- a/packages/core/src/CommandManager.ts
+++ b/packages/core/src/CommandManager.ts
@@ -1,9 +1,9 @@
 import { EditorState, Transaction } from 'prosemirror-state'
 import {
-  Editor,
-  CommandSpec,
   SingleCommands,
   ChainedCommands,
+  Editor,
+  CommandSpec,
 } from './Editor'
 import getAllMethodNames from './utils/getAllMethodNames'
 
diff --git a/packages/core/src/Editor.ts b/packages/core/src/Editor.ts
index e6dfcf4b53e..5791204a3ae 100644
--- a/packages/core/src/Editor.ts
+++ b/packages/core/src/Editor.ts
@@ -21,6 +21,8 @@ import { Extensions, UnionToIntersection } from './types'
 import * as extensions from './extensions'
 import style from './style'
 
+export { extensions }
+
 export type Command = (props: {
   editor: Editor,
   tr: Transaction,
@@ -38,25 +40,21 @@ export interface CommandsSpec {
   [key: string]: CommandSpec
 }
 
-declare global {
-  namespace Tiptap {
-    export interface AllExtensions {}
-  }
-}
+export interface AllExtensions {}
 
-type UnfilteredCommands = {
-  [Item in keyof Tiptap.AllExtensions]: Tiptap.AllExtensions[Item] extends Extension<any, infer ExtensionCommands>
+export type UnfilteredCommands = {
+  [Item in keyof AllExtensions]: AllExtensions[Item] extends Extension<any, infer ExtensionCommands>
     ? ExtensionCommands
-    : Tiptap.AllExtensions[Item] extends Node<any, infer NodeCommands>
+    : AllExtensions[Item] extends Node<any, infer NodeCommands>
       ? NodeCommands
-      : Tiptap.AllExtensions[Item] extends Mark<any, infer MarkCommands>
+      : AllExtensions[Item] extends Mark<any, infer MarkCommands>
         ? MarkCommands
         : never
 }
 
-type ValuesOf<T> = T[keyof T];
-type KeysWithTypeOf<T, Type> = ({[P in keyof T]: T[P] extends Type ? P : never })[keyof T]
-type AllCommands = UnionToIntersection<ValuesOf<Pick<UnfilteredCommands, KeysWithTypeOf<UnfilteredCommands, {}>>>>
+export type ValuesOf<T> = T[keyof T];
+export type KeysWithTypeOf<T, Type> = ({[P in keyof T]: T[P] extends Type ? P : never })[keyof T]
+export type AllCommands = UnionToIntersection<ValuesOf<Pick<UnfilteredCommands, KeysWithTypeOf<UnfilteredCommands, {}>>>>
 
 export type SingleCommands = {
   [Item in keyof AllCommands]: AllCommands[Item] extends (...args: any[]) => any
diff --git a/packages/core/src/extensions/commands.ts b/packages/core/src/extensions/commands.ts
index 63d3715bae7..3b82b620a9c 100644
--- a/packages/core/src/extensions/commands.ts
+++ b/packages/core/src/extensions/commands.ts
@@ -147,10 +147,8 @@ export const Commands = Extension.create({
   },
 })
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Commands: typeof Commands,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Commands: typeof Commands,
   }
 }
diff --git a/packages/core/src/extensions/editable.ts b/packages/core/src/extensions/editable.ts
index dc609ff983c..4dc9f2d0813 100644
--- a/packages/core/src/extensions/editable.ts
+++ b/packages/core/src/extensions/editable.ts
@@ -14,10 +14,8 @@ export const Editable = Extension.create({
   },
 })
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Editable: typeof Editable,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Editable: typeof Editable,
   }
 }
diff --git a/packages/core/src/extensions/focusEvents.ts b/packages/core/src/extensions/focusEvents.ts
index f5be8311d5d..468d105fa39 100644
--- a/packages/core/src/extensions/focusEvents.ts
+++ b/packages/core/src/extensions/focusEvents.ts
@@ -36,10 +36,8 @@ export const FocusEvents = Extension.create({
   },
 })
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      FocusEvents: typeof FocusEvents,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    FocusEvents: typeof FocusEvents,
   }
 }
diff --git a/packages/core/src/extensions/keymap.ts b/packages/core/src/extensions/keymap.ts
index 99c87781b1f..99486512e25 100644
--- a/packages/core/src/extensions/keymap.ts
+++ b/packages/core/src/extensions/keymap.ts
@@ -45,10 +45,8 @@ export const Keymap = Extension.create({
   },
 })
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Keymap: typeof Keymap,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Keymap: typeof Keymap,
   }
 }
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 97316c91406..a1aa1c8575c 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -1,9 +1,4 @@
-export {
-  Editor,
-  Command,
-  CommandsSpec,
-} from './Editor'
-
+export * from './Editor'
 export * from './Extension'
 export * from './Node'
 export * from './Mark'
diff --git a/packages/extension-blockquote/src/index.ts b/packages/extension-blockquote/src/index.ts
index d29a4c935b7..d0d3f318abf 100644
--- a/packages/extension-blockquote/src/index.ts
+++ b/packages/extension-blockquote/src/index.ts
@@ -58,10 +58,8 @@ const Blockquote = Node.create({
 
 export default Blockquote
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Blockquote: typeof Blockquote,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Blockquote: typeof Blockquote,
   }
 }
diff --git a/packages/extension-bold/src/index.ts b/packages/extension-bold/src/index.ts
index 59fe2c7fd42..64ff675e70a 100644
--- a/packages/extension-bold/src/index.ts
+++ b/packages/extension-bold/src/index.ts
@@ -74,10 +74,8 @@ const Bold = Mark.create({
 
 export default Bold
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Bold: typeof Bold,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Bold: typeof Bold,
   }
 }
diff --git a/packages/extension-bullet-list/src/index.ts b/packages/extension-bullet-list/src/index.ts
index fbb6d9ae3ea..3fa2338b611 100644
--- a/packages/extension-bullet-list/src/index.ts
+++ b/packages/extension-bullet-list/src/index.ts
@@ -56,10 +56,8 @@ const BulletList = Node.create({
 
 export default BulletList
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      BulletList: typeof BulletList,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    BulletList: typeof BulletList,
   }
 }
diff --git a/packages/extension-code-block/src/index.ts b/packages/extension-code-block/src/index.ts
index 1c6e870ca85..2d697e9d0df 100644
--- a/packages/extension-code-block/src/index.ts
+++ b/packages/extension-code-block/src/index.ts
@@ -99,10 +99,8 @@ const CodeBlock = Node.create({
 
 export default CodeBlock
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      CodeBlock: typeof CodeBlock,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    CodeBlock: typeof CodeBlock,
   }
 }
diff --git a/packages/extension-code/src/index.ts b/packages/extension-code/src/index.ts
index 6445ec5f2d6..5eb5909ecfb 100644
--- a/packages/extension-code/src/index.ts
+++ b/packages/extension-code/src/index.ts
@@ -65,10 +65,8 @@ const Code = Mark.create({
 
 export default Code
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Code: typeof Code,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Code: typeof Code,
   }
 }
diff --git a/packages/extension-collaboration-cursor/src/index.ts b/packages/extension-collaboration-cursor/src/index.ts
index a4fb97e3680..ae88704cb89 100644
--- a/packages/extension-collaboration-cursor/src/index.ts
+++ b/packages/extension-collaboration-cursor/src/index.ts
@@ -64,10 +64,8 @@ const CollaborationCursor = Extension.create({
 
 export default CollaborationCursor
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      CollaborationCursor: typeof CollaborationCursor,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    CollaborationCursor: typeof CollaborationCursor,
   }
 }
diff --git a/packages/extension-collaboration/src/index.ts b/packages/extension-collaboration/src/index.ts
index 3ed695ee90c..729ef245bab 100644
--- a/packages/extension-collaboration/src/index.ts
+++ b/packages/extension-collaboration/src/index.ts
@@ -32,10 +32,8 @@ const Collaboration = Extension.create({
 
 export default Collaboration
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Collaboration: typeof Collaboration,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Collaboration: typeof Collaboration,
   }
 }
diff --git a/packages/extension-document/src/index.ts b/packages/extension-document/src/index.ts
index efec4dd5f5b..5c9b4796164 100644
--- a/packages/extension-document/src/index.ts
+++ b/packages/extension-document/src/index.ts
@@ -8,10 +8,8 @@ const Document = Node.create({
 
 export default Document
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Document: typeof Document,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Document: typeof Document,
   }
 }
diff --git a/packages/extension-dropcursor/src/index.ts b/packages/extension-dropcursor/src/index.ts
index acbf2866aca..fd951be21a3 100644
--- a/packages/extension-dropcursor/src/index.ts
+++ b/packages/extension-dropcursor/src/index.ts
@@ -11,10 +11,8 @@ const Dropcursor = Extension.create({
 
 export default Dropcursor
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Dropcursor: typeof Dropcursor,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Dropcursor: typeof Dropcursor,
   }
 }
diff --git a/packages/extension-focus/src/index.ts b/packages/extension-focus/src/index.ts
index 10c517e7eb9..62c7844c36b 100644
--- a/packages/extension-focus/src/index.ts
+++ b/packages/extension-focus/src/index.ts
@@ -50,10 +50,8 @@ const FocusClasses = Extension.create({
 
 export default FocusClasses
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      FocusClasses: typeof FocusClasses,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    FocusClasses: typeof FocusClasses,
   }
 }
diff --git a/packages/extension-font-family/src/index.ts b/packages/extension-font-family/src/index.ts
index 4dbf17076e3..e83846dcf84 100644
--- a/packages/extension-font-family/src/index.ts
+++ b/packages/extension-font-family/src/index.ts
@@ -52,10 +52,8 @@ const FontFamily = Extension.create({
 
 export default FontFamily
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      FontFamily: typeof FontFamily,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    FontFamily: typeof FontFamily,
   }
 }
diff --git a/packages/extension-gapcursor/src/index.ts b/packages/extension-gapcursor/src/index.ts
index f295bef70c9..09ee3846059 100644
--- a/packages/extension-gapcursor/src/index.ts
+++ b/packages/extension-gapcursor/src/index.ts
@@ -11,10 +11,8 @@ const Gapcursor = Extension.create({
 
 export default Gapcursor
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Gapcursor: typeof Gapcursor,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Gapcursor: typeof Gapcursor,
   }
 }
diff --git a/packages/extension-hard-break/src/index.ts b/packages/extension-hard-break/src/index.ts
index dcaa9c4092f..677b094160a 100644
--- a/packages/extension-hard-break/src/index.ts
+++ b/packages/extension-hard-break/src/index.ts
@@ -50,10 +50,8 @@ const HardBreak = Node.create({
 
 export default HardBreak
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      HardBreak: typeof HardBreak,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    HardBreak: typeof HardBreak,
   }
 }
diff --git a/packages/extension-heading/src/index.ts b/packages/extension-heading/src/index.ts
index e94202639ee..c02b8a811ad 100644
--- a/packages/extension-heading/src/index.ts
+++ b/packages/extension-heading/src/index.ts
@@ -83,10 +83,8 @@ const Heading = Node.create({
 
 export default Heading
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Heading: typeof Heading,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Heading: typeof Heading,
   }
 }
diff --git a/packages/extension-highlight/src/index.ts b/packages/extension-highlight/src/index.ts
index c57adfe5a56..c3298aa6c38 100644
--- a/packages/extension-highlight/src/index.ts
+++ b/packages/extension-highlight/src/index.ts
@@ -88,10 +88,8 @@ const Highlight = Mark.create({
 
 export default Highlight
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Highlight: typeof Highlight,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Highlight: typeof Highlight,
   }
 }
diff --git a/packages/extension-history/src/index.ts b/packages/extension-history/src/index.ts
index 12e6ed7af7b..6f389f2ea45 100644
--- a/packages/extension-history/src/index.ts
+++ b/packages/extension-history/src/index.ts
@@ -46,10 +46,8 @@ const History = Extension.create({
 
 export default History
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      History: typeof History,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    History: typeof History,
   }
 }
diff --git a/packages/extension-horizontal-rule/src/index.ts b/packages/extension-horizontal-rule/src/index.ts
index d8f0e04d4f7..ebab3e3bd3c 100644
--- a/packages/extension-horizontal-rule/src/index.ts
+++ b/packages/extension-horizontal-rule/src/index.ts
@@ -47,10 +47,8 @@ const HorizontalRule = Node.create({
 
 export default HorizontalRule
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      HorizontalRule: typeof HorizontalRule,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    HorizontalRule: typeof HorizontalRule,
   }
 }
diff --git a/packages/extension-image/src/index.ts b/packages/extension-image/src/index.ts
index 9a8bfd938a7..7eeb831ba1d 100644
--- a/packages/extension-image/src/index.ts
+++ b/packages/extension-image/src/index.ts
@@ -82,10 +82,8 @@ const Image = Node.create({
 
 export default Image
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Image: typeof Image,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Image: typeof Image,
   }
 }
diff --git a/packages/extension-italic/src/index.ts b/packages/extension-italic/src/index.ts
index 4b2261867ab..9843f65ec52 100644
--- a/packages/extension-italic/src/index.ts
+++ b/packages/extension-italic/src/index.ts
@@ -76,10 +76,8 @@ const Italic = Mark.create({
 
 export default Italic
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Italic: typeof Italic,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Italic: typeof Italic,
   }
 }
diff --git a/packages/extension-link/src/index.ts b/packages/extension-link/src/index.ts
index 9aaf2f16adb..3570b998011 100644
--- a/packages/extension-link/src/index.ts
+++ b/packages/extension-link/src/index.ts
@@ -93,10 +93,8 @@ const Link = Mark.create({
 
 export default Link
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Link: typeof Link,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Link: typeof Link,
   }
 }
diff --git a/packages/extension-list-item/src/index.ts b/packages/extension-list-item/src/index.ts
index bf587470f9b..b0d88118cff 100644
--- a/packages/extension-list-item/src/index.ts
+++ b/packages/extension-list-item/src/index.ts
@@ -40,10 +40,8 @@ const ListItem = Node.create({
 
 export default ListItem
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      ListItem: typeof ListItem,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    ListItem: typeof ListItem,
   }
 }
diff --git a/packages/extension-ordered-list/src/index.ts b/packages/extension-ordered-list/src/index.ts
index da0b4afa897..d20b361a84c 100644
--- a/packages/extension-ordered-list/src/index.ts
+++ b/packages/extension-ordered-list/src/index.ts
@@ -80,10 +80,8 @@ const OrderedList = Node.create({
 
 export default OrderedList
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      OrderedList: typeof OrderedList,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    OrderedList: typeof OrderedList,
   }
 }
diff --git a/packages/extension-paragraph/src/index.ts b/packages/extension-paragraph/src/index.ts
index d9712f1bd66..961d08eb5d9 100644
--- a/packages/extension-paragraph/src/index.ts
+++ b/packages/extension-paragraph/src/index.ts
@@ -47,10 +47,8 @@ const Paragraph = Node.create({
 
 export default Paragraph
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Paragraph: typeof Paragraph,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Paragraph: typeof Paragraph,
   }
 }
diff --git a/packages/extension-strike/src/index.ts b/packages/extension-strike/src/index.ts
index b74df416851..197e949eca0 100644
--- a/packages/extension-strike/src/index.ts
+++ b/packages/extension-strike/src/index.ts
@@ -74,10 +74,8 @@ const Strike = Mark.create({
 
 export default Strike
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Strike: typeof Strike,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Strike: typeof Strike,
   }
 }
diff --git a/packages/extension-task-item/src/index.ts b/packages/extension-task-item/src/index.ts
index 18202b4a015..ce7c0ab3ca1 100644
--- a/packages/extension-task-item/src/index.ts
+++ b/packages/extension-task-item/src/index.ts
@@ -125,10 +125,8 @@ const TaskItem = Node.create({
 
 export default TaskItem
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      TaskItem: typeof TaskItem,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    TaskItem: typeof TaskItem,
   }
 }
diff --git a/packages/extension-task-list/src/index.ts b/packages/extension-task-list/src/index.ts
index c5c1d17117b..554cf283714 100644
--- a/packages/extension-task-list/src/index.ts
+++ b/packages/extension-task-list/src/index.ts
@@ -44,10 +44,8 @@ const TaskList = Node.create({
 
 export default TaskList
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      TaskList: typeof TaskList,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    TaskList: typeof TaskList,
   }
 }
diff --git a/packages/extension-text-align/src/index.ts b/packages/extension-text-align/src/index.ts
index 46847db1b6e..63fb2279d0c 100644
--- a/packages/extension-text-align/src/index.ts
+++ b/packages/extension-text-align/src/index.ts
@@ -65,10 +65,8 @@ const TextAlign = Extension.create({
 
 export default TextAlign
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      TextAlign: typeof TextAlign,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    TextAlign: typeof TextAlign,
   }
 }
diff --git a/packages/extension-text-style/src/index.ts b/packages/extension-text-style/src/index.ts
index aaea4511c18..bed66e3246a 100644
--- a/packages/extension-text-style/src/index.ts
+++ b/packages/extension-text-style/src/index.ts
@@ -46,10 +46,8 @@ const TextStyle = Mark.create({
 
 export default TextStyle
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      TextStyle: typeof TextStyle,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    TextStyle: typeof TextStyle,
   }
 }
diff --git a/packages/extension-text/src/index.ts b/packages/extension-text/src/index.ts
index 2180e1c25e0..b6bea78dec2 100644
--- a/packages/extension-text/src/index.ts
+++ b/packages/extension-text/src/index.ts
@@ -7,10 +7,8 @@ const Text = Node.create({
 
 export default Text
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Text: typeof Text,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Text: typeof Text,
   }
 }
diff --git a/packages/extension-typography/src/index.ts b/packages/extension-typography/src/index.ts
index 3b35dc939ac..34e696c4623 100644
--- a/packages/extension-typography/src/index.ts
+++ b/packages/extension-typography/src/index.ts
@@ -45,10 +45,8 @@ const Typography = Extension.create({
 
 export default Typography
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Typography: typeof Typography,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Typography: typeof Typography,
   }
 }
diff --git a/packages/extension-underline/src/index.ts b/packages/extension-underline/src/index.ts
index 4bfe1ee509e..0f9cb39c1ce 100644
--- a/packages/extension-underline/src/index.ts
+++ b/packages/extension-underline/src/index.ts
@@ -45,10 +45,8 @@ const Underline = Mark.create({
 
 export default Underline
 
-declare global {
-  namespace Tiptap {
-    interface AllExtensions {
-      Underline: typeof Underline,
-    }
+declare module '@tiptap/core' {
+  interface AllExtensions {
+    Underline: typeof Underline,
   }
 }