diff --git a/components/pwa/install-prompt.tsx b/components/pwa/install-prompt.tsx
index c1f2d40..a1996bf 100644
--- a/components/pwa/install-prompt.tsx
+++ b/components/pwa/install-prompt.tsx
@@ -44,8 +44,8 @@ export function InstallPrompt({ autoShow = false }: InstallPromptProps) {
   const { canInstall, installPrompt, isInstalled: pwaInstalled } = usePWA()
 
   useEffect(() => {
-    // Check if app is already installed
-    if (window.matchMedia && window.matchMedia('(display-mode: standalone)').matches) {
+    // Check if app is already installed (client-side only)
+    if (typeof window !== 'undefined' && window.matchMedia && window.matchMedia('(display-mode: standalone)').matches) {
       setIsInstalled(true)
     }
 
@@ -304,7 +304,7 @@ export function useInstallPrompt() {
   const [isInstalled, setIsInstalled] = useState(false)
 
   useEffect(() => {
-    if (window.matchMedia && window.matchMedia('(display-mode: standalone)').matches) {
+    if (typeof window !== 'undefined' && window.matchMedia && window.matchMedia('(display-mode: standalone)').matches) {
       setIsInstalled(true)
     }
   }, [])
diff --git a/components/pwa/service-worker-provider.tsx b/components/pwa/service-worker-provider.tsx
index c810a44..ba180e3 100644
--- a/components/pwa/service-worker-provider.tsx
+++ b/components/pwa/service-worker-provider.tsx
@@ -101,6 +101,8 @@ export function ServiceWorkerProvider({ children }: { children: React.ReactNode
   }
 
   const setupInstallPrompt = () => {
+    if (typeof window === 'undefined') return
+
     // Listen for beforeinstallprompt event
     window.addEventListener('beforeinstallprompt', (e) => {
       console.log('[PWA] Install prompt available')