diff --git a/packages/core/src/MarkExtension.ts b/packages/core/src/MarkExtension.ts
index 4627b681d..da1d1f41f 100644
--- a/packages/core/src/MarkExtension.ts
+++ b/packages/core/src/MarkExtension.ts
@@ -10,22 +10,22 @@ export interface MarkExtensionSpec<Options = {}, Commands = {}> extends Overwrit
   /**
    * Inclusive
    */
-  inclusive?: MarkSpec['inclusive'],
+  inclusive?: MarkSpec['inclusive'] | ((this: { options: Options }) => MarkSpec['inclusive']),
 
   /**
    * Excludes
    */
-  excludes?: MarkSpec['excludes'],
+  excludes?: MarkSpec['excludes'] | ((this: { options: Options }) => MarkSpec['excludes']),
 
   /**
    * Group
    */
-  group?: MarkSpec['group'],
+  group?: MarkSpec['group'] | ((this: { options: Options }) => MarkSpec['group']),
 
   /**
    * Spanning
    */
-  spanning?: MarkSpec['spanning'],
+  spanning?: MarkSpec['spanning'] | ((this: { options: Options }) => MarkSpec['spanning']),
 
   /**
    * Parse HTML
diff --git a/packages/core/src/NodeExtension.ts b/packages/core/src/NodeExtension.ts
index 17d6e91d6..37e6f2fcb 100644
--- a/packages/core/src/NodeExtension.ts
+++ b/packages/core/src/NodeExtension.ts
@@ -15,52 +15,52 @@ export interface NodeExtensionSpec<Options = {}, Commands = {}> extends Overwrit
   /**
    * Content
    */
-  content?: NodeSpec['content'],
+  content?: NodeSpec['content'] | ((this: { options: Options }) => NodeSpec['content']),
 
   /**
    * Marks
    */
-  marks?: NodeSpec['marks'],
+  marks?: NodeSpec['marks'] | ((this: { options: Options }) => NodeSpec['marks']),
 
   /**
    * Group
    */
-  group?: NodeSpec['group'],
+  group?: NodeSpec['group'] | ((this: { options: Options }) => NodeSpec['group']),
 
   /**
    * Inline
    */
-  inline?: NodeSpec['inline'],
+  inline?: NodeSpec['inline'] | ((this: { options: Options }) => NodeSpec['inline']),
 
   /**
    * Atom
    */
-  atom?: NodeSpec['atom'],
+  atom?: NodeSpec['atom'] | ((this: { options: Options }) => NodeSpec['atom']),
 
   /**
    * Selectable
    */
-  selectable?: NodeSpec['selectable'],
+  selectable?: NodeSpec['selectable'] | ((this: { options: Options }) => NodeSpec['selectable']),
 
   /**
    * Draggable
    */
-  draggable?: NodeSpec['draggable'],
+  draggable?: NodeSpec['draggable'] | ((this: { options: Options }) => NodeSpec['draggable']),
 
   /**
    * Code
    */
-  code?: NodeSpec['code'],
+  code?: NodeSpec['code'] | ((this: { options: Options }) => NodeSpec['code']),
 
   /**
    * Defining
    */
-  defining?: NodeSpec['defining'],
+  defining?: NodeSpec['defining'] | ((this: { options: Options }) => NodeSpec['defining']),
 
   /**
    * Isolating
    */
-  isolating?: NodeSpec['isolating'],
+  isolating?: NodeSpec['isolating'] | ((this: { options: Options }) => NodeSpec['isolating']),
 
   /**
    * Parse HTML
diff --git a/packages/core/src/utils/callOrReturn.ts b/packages/core/src/utils/callOrReturn.ts
new file mode 100644
index 000000000..55e78e0db
--- /dev/null
+++ b/packages/core/src/utils/callOrReturn.ts
@@ -0,0 +1,17 @@
+/**
+ * Optionally calls `value` as a function.
+ * Otherwise it is returned directly.
+ * @param value Function or any value.
+ * @param context Optional context to bind to function.
+ */
+export default function callOrReturn(value: any, context?: any) {
+  if (typeof value === 'function') {
+    if (context) {
+      return value.bind(context)()
+    }
+
+    return value()
+  }
+
+  return value
+}
diff --git a/packages/core/src/utils/getSchema.ts b/packages/core/src/utils/getSchema.ts
index 817ed7a8d..1a191f50f 100644
--- a/packages/core/src/utils/getSchema.ts
+++ b/packages/core/src/utils/getSchema.ts
@@ -5,6 +5,7 @@ import getAttributesFromExtensions from './getAttributesFromExtensions'
 import getRenderedAttributes from './getRenderedAttributes'
 import isEmptyObject from './isEmptyObject'
 import injectExtensionAttributesToParseRule from './injectExtensionAttributesToParseRule'
+import callOrReturn from './callOrReturn'
 
 function cleanUpSchemaItem<T>(data: T) {
   return Object.fromEntries(Object.entries(data).filter(([key, value]) => {
@@ -25,16 +26,16 @@ export default function getSchema(extensions: Extensions): Schema {
     const extensionAttributes = allAttributes.filter(attribute => attribute.type === extension.name)
     const context = { options: extension.options }
     const schema: NodeSpec = cleanUpSchemaItem({
-      content: extension.content,
-      marks: extension.marks,
-      group: extension.group,
-      inline: extension.inline,
-      atom: extension.atom,
-      selectable: extension.selectable,
-      draggable: extension.draggable,
-      code: extension.code,
-      defining: extension.defining,
-      isolating: extension.isolating,
+      content: callOrReturn(extension.content, context),
+      marks: callOrReturn(extension.marks, context),
+      group: callOrReturn(extension.group, context),
+      inline: callOrReturn(extension.inline, context),
+      atom: callOrReturn(extension.atom, context),
+      selectable: callOrReturn(extension.selectable, context),
+      draggable: callOrReturn(extension.draggable, context),
+      code: callOrReturn(extension.code, context),
+      defining: callOrReturn(extension.defining, context),
+      isolating: callOrReturn(extension.isolating, context),
       attrs: Object.fromEntries(extensionAttributes.map(extensionAttribute => {
         return [extensionAttribute.name, { default: extensionAttribute?.attribute?.default }]
       })),
@@ -60,10 +61,10 @@ export default function getSchema(extensions: Extensions): Schema {
     const extensionAttributes = allAttributes.filter(attribute => attribute.type === extension.name)
     const context = { options: extension.options }
     const schema: MarkSpec = cleanUpSchemaItem({
-      inclusive: extension.inclusive,
-      excludes: extension.excludes,
-      group: extension.group,
-      spanning: extension.spanning,
+      inclusive: callOrReturn(extension.inclusive, context),
+      excludes: callOrReturn(extension.excludes, context),
+      group: callOrReturn(extension.group, context),
+      spanning: callOrReturn(extension.spanning, context),
       attrs: Object.fromEntries(extensionAttributes.map(extensionAttribute => {
         return [extensionAttribute.name, { default: extensionAttribute?.attribute?.default }]
       })),
diff --git a/packages/extension-task-item/index.ts b/packages/extension-task-item/index.ts
index 283296cf2..dc91de8a7 100644
--- a/packages/extension-task-item/index.ts
+++ b/packages/extension-task-item/index.ts
@@ -7,12 +7,9 @@ export interface TaskItemOptions {
 const TaskItem = createNode({
   name: 'task_item',
 
-  content: 'paragraph+',
-
-  // TODO: allow content to be a callback function
-  // content() {
-  //   return this.options.nested ? '(paragraph|todo_list)+' : 'paragraph+',
-  // },
+  content() {
+    return this.options.nested ? '(paragraph|task_list)+' : 'paragraph+'
+  },
 
   defining: true,