diff --git a/app/Dockerfile b/app/Dockerfile
index 05c0810..df4ac77 100644
--- a/app/Dockerfile
+++ b/app/Dockerfile
@@ -14,6 +14,7 @@ RUN apt-get update \
       jq \
       netcat \
       ca-certificates \
+      xmlsec1 \
     && rm -rf /var/lib/apt/lists/* /var/cache/apt/archives/*.deb /var/cache/apt/archives/partial/*.deb /var/cache/apt/*.bin
 
 # Get Mattermost