diff --git a/firebase.json b/firebase.json
index d3cec544b0e9..b87921648d16 100644
--- a/firebase.json
+++ b/firebase.json
@@ -14,6 +14,10 @@
           {
             "key": "Cache-Control",
             "value": "no-cache"
+          },
+          {
+            "key": "X-Frame-Options",
+            "value": "DENY"
           }
         ]
       }