From 5beb2943b94769bce6ed3f9c5d2738a5de590a70 Mon Sep 17 00:00:00 2001
From: Benny Joo <sldisek783@gmail.com>
Date: Mon, 12 May 2025 13:59:37 -0400
Subject: [PATCH] fix: localStorage error in useTheme (#21258)

---
 packages/lib/hooks/useTheme.tsx | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/lib/hooks/useTheme.tsx b/packages/lib/hooks/useTheme.tsx
index 3c9afa622e..e58b661818 100644
--- a/packages/lib/hooks/useTheme.tsx
+++ b/packages/lib/hooks/useTheme.tsx
@@ -12,7 +12,9 @@ import { useEmbedTheme } from "@calcom/embed-core/embed-iframe";
 // eslint-disable-next-line @typescript-eslint/ban-types
 export default function useTheme(themeToSet: "system" | (string & {}) | undefined | null, getOnly = false) {
   if (typeof window !== "undefined") {
-    themeToSet = themeToSet || localStorage.getItem("app-theme") || "system";
+    const themeFromLocalStorage =
+      typeof window !== "undefined" && window.localStorage ? localStorage.getItem("app-theme") : null;
+    themeToSet = themeToSet ?? themeFromLocalStorage ?? "system";
   }
   const { resolvedTheme, setTheme, forcedTheme, theme: activeTheme } = useNextTheme();
   const embedTheme = useEmbedTheme();