diff --git a/firebase.json b/firebase.json
index 93aabb7..ebaeefa 100644
--- a/firebase.json
+++ b/firebase.json
@@ -26,7 +26,7 @@
         ]
       },
       {
-        "source": "!(img)/**/*.@(jpg|jpeg|png|webp)",
+        "regex": "^/(?:[^i]|i[^m]|im[^g])[^/]*/.*[.](?:jpg|jpeg|png|webp)$",
         "headers": [
           {
             "key": "Cache-Control",