diff --git a/.changeset/cool-peaches-burn.md b/.changeset/cool-peaches-burn.md
new file mode 100644
index 000000000..6bc06d2aa
--- /dev/null
+++ b/.changeset/cool-peaches-burn.md
@@ -0,0 +1,11 @@
+---
+'@lion/combobox': minor
+'@lion/form-core': patch
+'@lion/form-integrations': patch
+---
+
+Allow Subclassers of LionCombobox to set '\_syncToTextboxCondition' in closing phase of overlay
+
+## Fixes
+
+Allow an extra microtask in registration phase to make forms inside dialogs compatible.
diff --git a/docs/components/inputs/combobox/features.md b/docs/components/inputs/combobox/features.md
index 801d06bef..5a8cdd9a5 100644
--- a/docs/components/inputs/combobox/features.md
+++ b/docs/components/inputs/combobox/features.md
@@ -215,7 +215,10 @@ This will:
 ```js preview-story
 export const multipleChoice = () => html`
   <lion-combobox name="combo" label="Multiple" multiple-choice>
-    <demo-selection-display slot="selection-display"></demo-selection-display>
+    <demo-selection-display
+      slot="selection-display"
+      style="display: contents;"
+    ></demo-selection-display>
     ${lazyRender(
       listboxData.map(
         (entry, i) =>
diff --git a/packages/combobox/src/LionCombobox.js b/packages/combobox/src/LionCombobox.js
index 0d4b394e7..b377bbf76 100644
--- a/packages/combobox/src/LionCombobox.js
+++ b/packages/combobox/src/LionCombobox.js
@@ -440,7 +440,12 @@ export class LionCombobox extends OverlayMixin(LionListbox) {
 
   __onOverlayClose() {
     if (!this.multipleChoice) {
-      if (this.checkedIndex !== -1) {
+      if (
+        this.checkedIndex !== -1 &&
+        this._syncToTextboxCondition(this.modelValue, this.__oldModelValue, {
+          phase: 'overlay-close',
+        })
+      ) {
         this._inputNode.value = this.formElements[
           /** @type {number} */ (this.checkedIndex)
         ].choiceValue;
@@ -739,12 +744,15 @@ export class LionCombobox extends OverlayMixin(LionListbox) {
   }
 
   /**
+   * @overridable
    * @param {string|string[]} modelValue
    * @param {string|string[]} oldModelValue
    */
   // eslint-disable-next-line no-unused-vars
-  _syncToTextboxCondition(modelValue, oldModelValue) {
-    return this.autocomplete === 'inline' || this.autocomplete === 'both';
+  _syncToTextboxCondition(modelValue, oldModelValue, { phase } = {}) {
+    return (
+      this.autocomplete === 'inline' || this.autocomplete === 'both' || phase === 'overlay-close'
+    );
   }
 
   /**
diff --git a/packages/combobox/test/lion-combobox.test.js b/packages/combobox/test/lion-combobox.test.js
index f95242c75..4870f59b7 100644
--- a/packages/combobox/test/lion-combobox.test.js
+++ b/packages/combobox/test/lion-combobox.test.js
@@ -936,6 +936,46 @@ describe('lion-combobox', () => {
       await performChecks('both', [0, 1], '');
     });
 
+    it('is possible to adjust textbox synchronize condition on overlay close', async () => {
+      const el = /** @type {LionCombobox} */ (await fixture(html`
+        <lion-combobox name="foo" autocomplete="none" ._syncToTextboxCondition="${() => false}">
+          <lion-option .choiceValue="${'Artichoke'}">Artichoke</lion-option>
+          <lion-option .choiceValue="${'Chard'}">Chard</lion-option>
+          <lion-option .choiceValue="${'Chicory'}">Chicory</lion-option>
+          <lion-option .choiceValue="${'Victoria Plum'}">Victoria Plum</lion-option>
+        </lion-combobox>
+      `));
+      expect(el._inputNode.value).to.equal('');
+
+      /**
+       * @param {'none' | 'list' | 'inline' | 'both'} autocomplete
+       * @param {number|number[]} index
+       * @param {string} valueOnClose
+       */
+      async function performChecks(autocomplete, index, valueOnClose) {
+        await el.updateComplete;
+        el.opened = true;
+        el.setCheckedIndex(-1);
+        await el.updateComplete;
+        el.autocomplete = autocomplete;
+        el.setCheckedIndex(index);
+        el.opened = false;
+        await el.updateComplete;
+        expect(el._inputNode.value).to.equal(valueOnClose);
+      }
+
+      await performChecks('none', 0, '');
+      await performChecks('list', 0, '');
+      await performChecks('inline', 0, '');
+      await performChecks('both', 0, '');
+
+      el.multipleChoice = true;
+      await performChecks('none', [0, 1], '');
+      await performChecks('list', [0, 1], '');
+      await performChecks('inline', [0, 1], '');
+      await performChecks('both', [0, 1], '');
+    });
+
     it('does inline autocompletion when adding chars', async () => {
       const el = /** @type {LionCombobox} */ (await fixture(html`
         <lion-combobox name="foo" autocomplete="inline">