diff --git a/Jenkinsfile b/Jenkinsfile
index 2703c90..c80e677 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -25,9 +25,9 @@ pipeline {
       steps {
         script {
           dockerImageObj.inside() {
-            sh 'echo "INSIDE CONTAINER!"'
-            sh '/usr/bin/python3 /app/sos-milter.py &'
-            sh 'sleep 5; if [ -S /socket/sos-milter ]; then exit 0; else exit 1; fi'
+            sh 'echo "Performing application tests inside sos-milter container..."'
+            sh 'export MILTER_SOCKET=inet:8020 && /usr/bin/python3 /app/sos-milter.py &'
+            sh 'sleep 5; /bin/nc -z -n -v -w 1 127.0.0.1 8020 || exit 1'
           }
         }
       }
diff --git a/docker/debian/Dockerfile b/docker/debian/Dockerfile
index 740d90d..32a7298 100644
--- a/docker/debian/Dockerfile
+++ b/docker/debian/Dockerfile
@@ -12,7 +12,7 @@ RUN env; set -ex ; \
  && apt-get -qq --no-install-recommends install \
      python3-pip python3-setuptools \
      libmilter1.0.1 libmilter-dev procps net-tools \
-     gcc python3-dev \
+     gcc python3-dev netcat-traditional \
  && /usr/bin/pip3 install pymilter \
  && /usr/bin/pip3 install dnspython \
  && /bin/mkdir /config /socket /app \