diff --git a/.changeset/clean-bugs-rush.md b/.changeset/clean-bugs-rush.md
new file mode 100644
index 000000000..a6a10a152
--- /dev/null
+++ b/.changeset/clean-bugs-rush.md
@@ -0,0 +1,5 @@
+---
+"@tiptap/core": patch
+---
+
+There was a bug where doing a `.configure` on an extension, node or mark would overwrite the extensions options instead of being merged with the default options.
diff --git a/packages/core/src/Extension.ts b/packages/core/src/Extension.ts
index e6e790bbf..97200301f 100644
--- a/packages/core/src/Extension.ts
+++ b/packages/core/src/Extension.ts
@@ -459,8 +459,8 @@ export class Extension<Options = any, Storage = any> {
     // with different calls of `configure`
     const extension = this.extend({
       ...this.config,
-      addOptions() {
-        return mergeDeep(this.parent?.() || {}, options) as Options
+      addOptions: () => {
+        return mergeDeep(this.options as Record<string, any>, options) as Options
       },
     })
 
diff --git a/packages/core/src/Mark.ts b/packages/core/src/Mark.ts
index 9ff572b0f..f365ce40e 100644
--- a/packages/core/src/Mark.ts
+++ b/packages/core/src/Mark.ts
@@ -591,8 +591,8 @@ export class Mark<Options = any, Storage = any> {
     // with different calls of `configure`
     const extension = this.extend({
       ...this.config,
-      addOptions() {
-        return mergeDeep(this.parent?.() || {}, options) as Options
+      addOptions: () => {
+        return mergeDeep(this.options as Record<string, any>, options) as Options
       },
     })
 
diff --git a/packages/core/src/Node.ts b/packages/core/src/Node.ts
index c1fd865f7..a79d3a9aa 100644
--- a/packages/core/src/Node.ts
+++ b/packages/core/src/Node.ts
@@ -782,8 +782,8 @@ export class Node<Options = any, Storage = any> {
     // with different calls of `configure`
     const extension = this.extend({
       ...this.config,
-      addOptions() {
-        return mergeDeep(this.parent?.() || {}, options) as Options
+      addOptions: () => {
+        return mergeDeep(this.options as Record<string, any>, options) as Options
       },
     })
 
diff --git a/tests/cypress/integration/core/extendExtensions.spec.ts b/tests/cypress/integration/core/extendExtensions.spec.ts
index f57838a19..b6618cc4f 100644
--- a/tests/cypress/integration/core/extendExtensions.spec.ts
+++ b/tests/cypress/integration/core/extendExtensions.spec.ts
@@ -393,26 +393,47 @@ describe('extend extensions', () => {
         })
       })
 
+      it('should configure to be in addition to the parent options', () => {
+        const parentExtension = Extendable
+          .create({
+            name: 'parentExtension',
+            addOptions() {
+              return { parent: 'exists', overwrite: 'parent' }
+            },
+          })
+
+        const childExtension = parentExtension
+          .configure({ child: 'exists-too', overwrite: 'child' })
+
+        expect(childExtension.options).to.deep.eq({
+          parent: 'exists',
+          child: 'exists-too',
+          overwrite: 'child',
+        })
+      })
+
       it('should deeply merge options when extending a configured extension', () => {
         const parentExtension = Extendable
           .create({
             name: 'parentExtension',
             addOptions() {
-              return { defaultOptions: 'is-overwritten' }
+              return { defaultOptions: 'exists', overwrite: 'parent' }
             },
           })
 
         const childExtension = parentExtension
-          .configure({ configuredOptions: 'exists-too' }).extend({
+          .configure({ configuredOptions: 'exists-too', overwrite: 'configure' }).extend({
             name: 'childExtension',
             addOptions() {
-              return { ...this.parent?.(), additionalOptions: 'exist-too' }
+              return { ...this.parent?.(), additionalOptions: 'exist-too', overwrite: 'child' }
             },
           })
 
         expect(childExtension.options).to.deep.eq({
+          defaultOptions: 'exists',
           configuredOptions: 'exists-too',
           additionalOptions: 'exist-too',
+          overwrite: 'child',
         })
       })
     })