diff --git a/.ci/Jenkinsfile b/.ci/Jenkinsfile
index ff7a320..9eee19f 100644
--- a/.ci/Jenkinsfile
+++ b/.ci/Jenkinsfile
@@ -3,7 +3,7 @@ pipeline {
     stages {
         stage('Build') {
             steps {
-                sh 'docker run -v $PWD/Core_DOM:/Core_DOM logicalhacking:isabelle2019 isabelle build -D /Core_DOM'
+                sh 'docker run -v $PWD/Core_DOM:/Core_DOM logicalhacking:isabelle2020 isabelle build -D /Core_DOM'
             }
         }
     }