diff --git a/lib/supabase/client.ts b/lib/supabase/client.ts
index 792b457..28d53cc 100644
--- a/lib/supabase/client.ts
+++ b/lib/supabase/client.ts
@@ -1,8 +1,18 @@
 import { createBrowserClient } from '@supabase/ssr'
 
 export function createClient() {
-  return createBrowserClient(
-    process.env.NEXT_PUBLIC_SUPABASE_URL!,
-    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
-  )
+  const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL
+  const supabaseAnonKey = process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY
+
+  // During build/prerendering, env vars may not be available
+  // Return a placeholder that will be replaced at runtime
+  if (!supabaseUrl || !supabaseAnonKey) {
+    if (typeof window === 'undefined') {
+      // Server-side during build - return a mock that won't be used
+      return null as any
+    }
+    throw new Error('Missing Supabase environment variables')
+  }
+
+  return createBrowserClient(supabaseUrl, supabaseAnonKey)
 }