diff --git a/installation/nginx-cache-purge.sh.example b/installation/nginx-cache-purge.sh.example
index aaa195324..b2915321c 100755
--- a/installation/nginx-cache-purge.sh.example
+++ b/installation/nginx-cache-purge.sh.example
@@ -13,7 +13,7 @@ CACHE_DIRECTORY="/tmp/pleroma-media-cache"
 ## $3 - (optional) the number of parallel processes to run for grep.
 get_cache_files() {
     local max_parallel=${3-16}
-    find $2 -maxdepth 2 -type d | xargs -P $max_parallel -n 1 grep -ERl "^KEY:.*$1" | sort -u
+    find $2 -maxdepth 2 -type d | xargs -P $max_parallel -n 1 grep -E Rl "^KEY:.*$1" | sort -u
 }
 
 ## Removes an item from the given cache zone.