diff --git a/app/service-worker.js b/app/service-worker.js
index f8cd465..777230a 100644
--- a/app/service-worker.js
+++ b/app/service-worker.js
@@ -32,6 +32,8 @@ self.addEventListener('activate', event => {
 });
 
 self.addEventListener('fetch', event => {
+	if (event.request.method !== 'GET') return;
+
 	const url = new URL(event.request.url);
 
 	// don't try to handle e.g. data: URIs