diff --git a/Dockerfile b/Dockerfile
index fba32bf..0421a3d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,7 +5,7 @@ ARG MASTODON_REPOSITORY=tootsuite/mastodon
 ARG RUBY_VERSION=2.7.3
 ARG NODE_VERSION=14.17.0
 ARG ALPINE_VERSION=3.13
-ARG HARDENED_MALLOC_VERSION=8
+ARG HARDENED_MALLOC_VERSION=7
 ARG LIBICONV_VERSION=1.16
 
 ARG UID=991