diff --git a/Dockerfile b/Dockerfile
index 4b8f4fb..4a24d0e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -30,7 +30,6 @@
   && echo "$JENKINS_SHA /usr/share/jenkins/jenkins.war" | sha1sum -c -
 
 ENV JENKINS_UC https://updates.jenkins-ci.org
-ENV JENKINS_UC_DOWNLOAD $JENKINS_UC/download
 RUN chown -R jenkins "$JENKINS_HOME" /usr/share/jenkins/ref
 
 # for main web interface:
diff --git a/plugins.sh b/plugins.sh
index dc0f241..3413ce4 100755
--- a/plugins.sh
+++ b/plugins.sh
@@ -19,5 +19,9 @@
     [[ ${plugin[0]} =~ ^\s*$ ]] && continue
     [[ -z ${plugin[1]} ]] && plugin[1]="latest"
     echo "Downloading ${plugin[0]}:${plugin[1]}"
+
+    if [ -z "$JENKINS_UC_DOWNLOAD" ]; then
+      JENKINS_UC_DOWNLOAD=$JENKINS_UC/download
+    fi
     curl -sSL -f ${JENKINS_UC_DOWNLOAD}/plugins/${plugin[0]}/${plugin[1]}/${plugin[0]}.hpi -o $REF/${plugin[0]}.jpi
 done  < $1