From 1ef2828989f230fc4938a7b79930773a9b7b854d Mon Sep 17 00:00:00 2001
From: atomiks <cc.glows@gmail.com>
Date: Mon, 14 Oct 2024 13:42:23 +1100
Subject: [PATCH] Handle null default value

---
 packages/mui-base/src/Select/Root/useSelectRoot.tsx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/mui-base/src/Select/Root/useSelectRoot.tsx b/packages/mui-base/src/Select/Root/useSelectRoot.tsx
index b5231a057..b64808ce0 100644
--- a/packages/mui-base/src/Select/Root/useSelectRoot.tsx
+++ b/packages/mui-base/src/Select/Root/useSelectRoot.tsx
@@ -99,7 +99,8 @@ export function useSelectRoot(params: useSelectRoot.Parameters): useSelectRoot.R
   useEnhancedEffect(() => {
     // Wait for the items to have registered their values in `valuesRef`.
     queueMicrotask(() => {
-      const stringValue = typeof value === 'string' ? value : JSON.stringify(value);
+      const stringValue =
+        typeof value === 'string' || value === null ? value : JSON.stringify(value);
       const index = valuesRef.current.indexOf(stringValue);
       if (index !== -1) {
         setSelectedIndex(index);