diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2fe45169a2..709c47d0b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 - Include source maps for Parchment
 - **Clipboard** Support pasting links copied from iOS share sheets
+- Fix config parsing where undefined values were kept
 
 # 2.0.0-rc.3
 
diff --git a/package-lock.json b/package-lock.json
index acb31d6882..a235b62280 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12190,8 +12190,9 @@
       }
     },
     "node_modules/parchment": {
-      "version": "3.0.0-alpha.2",
-      "license": "BSD-3-Clause"
+      "version": "3.0.0-rc.0",
+      "resolved": "https://registry.npmjs.org/parchment/-/parchment-3.0.0-rc.0.tgz",
+      "integrity": "sha512-JyVx3qaAkFPOCrJpENNYnQkxBYRbo9oPEU2LMJX4g1czXmwtzLDWztFRe90BXrw/LBRLDfZpHcL8TvIGkS1vIA=="
     },
     "node_modules/parent-module": {
       "version": "1.0.1",
@@ -16071,7 +16072,7 @@
         "@reedsy/quill-delta": "^5.1.0-reedsy.3.0.0",
         "eventemitter3": "^5.0.1",
         "lodash-es": "^4.17.21",
-        "parchment": "3.0.0-alpha.2",
+        "parchment": "3.0.0-rc.0",
         "quill-delta": "^5.1.0"
       },
       "devDependencies": {
diff --git a/packages/quill/package.json b/packages/quill/package.json
index 11b073862e..d0f4c43dad 100644
--- a/packages/quill/package.json
+++ b/packages/quill/package.json
@@ -10,7 +10,7 @@
     "@reedsy/quill-delta": "^5.1.0-reedsy.3.0.0",
     "eventemitter3": "^5.0.1",
     "lodash-es": "^4.17.21",
-    "parchment": "3.0.0-alpha.2",
+    "parchment": "3.0.0-rc.0",
     "quill-delta": "^5.1.0"
   },
   "devDependencies": {
diff --git a/packages/quill/src/core/quill.ts b/packages/quill/src/core/quill.ts
index a20b7d1151..b20aa4bdfd 100644
--- a/packages/quill/src/core/quill.ts
+++ b/packages/quill/src/core/quill.ts
@@ -16,9 +16,10 @@ import instances from './instances.js';
 import logger from './logger.js';
 import type { DebugLevel } from './logger.js';
 import Module from './module.js';
-import Selection, { Range } from './selection.js';
+import type Selection from './selection.js';
+import { Range } from './selection.js';
 import type { Bounds } from './selection.js';
-import Composition from './composition.js';
+import type Composition from './composition.js';
 import Theme from './theme.js';
 import type { ThemeConstructor } from './theme.js';
 import scrollRectIntoView from './utils/scrollRectIntoView.js';
@@ -747,6 +748,12 @@ function expandModuleConfig(config: Record<string, unknown> | undefined) {
   );
 }
 
+function omitUndefinedValuesFromOptions(obj: Options) {
+  return Object.fromEntries(
+    Object.entries(obj).filter((entry) => entry[1] !== undefined),
+  );
+}
+
 function expandConfig(
   containerOrSelector: HTMLElement | string,
   options: Options,
@@ -785,7 +792,11 @@ function expandConfig(
     };
   }
 
-  const config = { ...quillDefaults, ...themeDefaults, ...options };
+  const config = {
+    ...quillDefaults,
+    ...omitUndefinedValuesFromOptions(themeDefaults),
+    ...omitUndefinedValuesFromOptions(options),
+  };
 
   let registry = options.registry;
   if (registry) {
diff --git a/packages/quill/test/e2e/full.spec.ts b/packages/quill/test/e2e/full.spec.ts
index f81279ac91..01e2b75a1b 100644
--- a/packages/quill/test/e2e/full.spec.ts
+++ b/packages/quill/test/e2e/full.spec.ts
@@ -3,15 +3,6 @@ import { getSelectionInTextNode, SHORTKEY } from './utils/index.js';
 import { test, CHAPTER, P1, P2 } from './fixtures/index.js';
 
 test('compose an epic', async ({ page, editorPage }) => {
-  const type = page.type.bind(page);
-  page.type = async (selector, text, options) => {
-    options = {
-      delay: 1,
-      ...options,
-    };
-    return type(selector, text, options);
-  };
-
   await editorPage.open();
   await editorPage.root.pressSequentially('The Whale');
   expect(await editorPage.root.innerHTML()).toEqual('<p>The Whale</p>');
diff --git a/packages/quill/test/unit/core/quill.spec.ts b/packages/quill/test/unit/core/quill.spec.ts
index 6e0a4fb93f..3aefc88853 100644
--- a/packages/quill/test/unit/core/quill.spec.ts
+++ b/packages/quill/test/unit/core/quill.spec.ts
@@ -790,6 +790,13 @@ describe('Quill', () => {
       expect(config.registry).toBe(globalRegistry);
     });
 
+    test('registry with undefined values', () => {
+      const config = expandConfig(`#${testContainerId}`, {
+        registry: undefined,
+      });
+      expect(config.registry).toBe(globalRegistry);
+    });
+
     describe('formats', () => {
       test('null value allows all formats', () => {
         const config = expandConfig(`#${testContainerId}`, {
@@ -800,6 +807,15 @@ describe('Quill', () => {
         expect(config.registry.query('bold')).toBeTruthy();
       });
 
+      test('undefined value allows all formats', () => {
+        const config = expandConfig(`#${testContainerId}`, {
+          formats: undefined,
+        });
+
+        expect(config.registry.query('cursor')).toBeTruthy();
+        expect(config.registry.query('bold')).toBeTruthy();
+      });
+
       test('always allows core formats', () => {
         const config = expandConfig(`#${testContainerId}`, {
           formats: ['bold'],