diff --git a/core/Dockerfile b/core/Dockerfile
index e66cfe5..3f8cfd3 100644
--- a/core/Dockerfile
+++ b/core/Dockerfile
@@ -11,8 +11,8 @@ RUN apk update \
 	   libffi-dev \
 	&& apk add --no-cache bash su-exec postgresql-client mysql-client curl python py3-setuptools \
 	&& python3 -m pip install -U pip \
-    && python3 -m pip install psycopg2 \
-                   mailman==3.2 \
+        && python3 -m pip install psycopg2 \
+                   mailman==3.2.2 \
                    mailman-hyperkitty==1.1.0 \
                    pymysql \
     && apk del build-deps \