diff --git a/_headers b/_headers
new file mode 100644
index 0000000..0995a4d
--- /dev/null
+++ b/_headers
@@ -0,0 +1,3 @@
+/*
+    Content-Security-Policy: default-src 'self'
+    X-Content-Type-Options: nosniff
\ No newline at end of file
diff --git a/build.sh b/build.sh
index 29f8ccd..cca88da 100755
--- a/build.sh
+++ b/build.sh
@@ -1,5 +1,5 @@
 mkdir -p build/@picocss/pico/css/
-cp *.png *.xml *.svg *.css *.webmanifest *.ico robots.txt build
+cp *.png *.xml *.svg *.css *.webmanifest *.ico robots.txt _headers build
 # https://github.com/cloudflare/workers-sdk/issues/3615
 sed 's/node_modules\///' index.html > build/index.html
 cp node_modules/@picocss/pico/css/pico.min.css build/@picocss/pico/css/
\ No newline at end of file