diff --git a/Dockerfile b/Dockerfile
index 9031336..4538b34 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,6 +3,7 @@ FROM alpine
 RUN apk add --no-cache \
     ca-certificates \
     curl \
+    file \
     iputils \
     mailx \
     nagios \
@@ -23,6 +24,7 @@ RUN apk add --no-cache \
     nagios-web \
     nrpe-plugin \
     openssh-client-common \
+    openssl \
     perl \
     python3 \
     py3-dnspython \
@@ -34,8 +36,9 @@ COPY FREE_send_notification.sh /usr/bin/FREE_send_notification.sh
 COPY entrypoint.sh /docker-entrypoint.sh
 
 ADD https://raw.githubusercontent.com/stump/check_sshfp/master/check_sshfp /usr/lib/nagios/plugins/check_sshfp
+ADD https://raw.githubusercontent.com/matteocorti/check_ssl_cert/master/check_ssl_cert /usr/lib/nagios/plugins/check_ssl_cert
 ADD https://gist.githubusercontent.com/nemunaire/9669659/raw/977cfce7246249c17e213b0b2b231220257754fa/nagios-status.pl /usr/bin/nagios-status.pl
-RUN chmod +x /usr/lib/nagios/plugins/check_sshfp /usr/bin/nagios-status.pl
+RUN chmod +x /usr/lib/nagios/plugins/check_sshfp /usr/lib/nagios/plugins/check_ssl_cert /usr/bin/nagios-status.pl
 
 ENTRYPOINT ["/docker-entrypoint.sh"]
 USER nagios