diff --git a/Dockerfile b/Dockerfile
index 8ec596c..ec28034 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 ARG SYNAPSE_VERSION=1.49.2
 ARG PYTHON_VERSION=3.9
 ARG ALPINE_VERSION=3.15
-ARG HARDENED_MALLOC_VERSION=8
+ARG HARDENED_MALLOC_VERSION=9
 ARG UID=991
 ARG GID=991