From 6e818d76d4bea22b0fc701828cdcbfe58fda24d5 Mon Sep 17 00:00:00 2001
From: Thomas Michon <tmichon@microsoft.com>
Date: Mon, 30 Aug 2021 10:31:34 -0700
Subject: [PATCH] Fix initialization of Responsive Mode on small screens
 (#18892)

---
 ...luentui-react-00695482-2fe3-44e4-bf1d-48d5d8a52851.json | 7 +++++++
 .../react/src/utilities/decorators/withResponsiveMode.tsx  | 4 ++--
 2 files changed, 9 insertions(+), 2 deletions(-)
 create mode 100644 change/@fluentui-react-00695482-2fe3-44e4-bf1d-48d5d8a52851.json

diff --git a/change/@fluentui-react-00695482-2fe3-44e4-bf1d-48d5d8a52851.json b/change/@fluentui-react-00695482-2fe3-44e4-bf1d-48d5d8a52851.json
new file mode 100644
index 0000000000000..0fcf023de8998
--- /dev/null
+++ b/change/@fluentui-react-00695482-2fe3-44e4-bf1d-48d5d8a52851.json
@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "Fix initial ResponsiveMode value",
+  "packageName": "@fluentui/react",
+  "email": "tmichon@microsoft.com",
+  "dependentChangeType": "patch"
+}
diff --git a/packages/react/src/utilities/decorators/withResponsiveMode.tsx b/packages/react/src/utilities/decorators/withResponsiveMode.tsx
index c721e0be6f5d8..ef98771c698fb 100644
--- a/packages/react/src/utilities/decorators/withResponsiveMode.tsx
+++ b/packages/react/src/utilities/decorators/withResponsiveMode.tsx
@@ -63,8 +63,8 @@ export function initializeResponsiveMode(element?: HTMLElement): void {
   }
 }
 
-export function getInitialResponsiveMode() {
-  return _defaultMode || _lastMode || ResponsiveMode.large;
+export function getInitialResponsiveMode(): ResponsiveMode {
+  return _defaultMode ?? _lastMode ?? ResponsiveMode.large;
 }
 
 /**