diff --git a/tests/CI/unittests.jenkinsfile b/tests/CI/unittests.jenkinsfile
index 43774fd8fa..96ea2133bf 100644
--- a/tests/CI/unittests.jenkinsfile
+++ b/tests/CI/unittests.jenkinsfile
@@ -183,8 +183,10 @@ pipeline {
 	}
 	post {
 		cleanup {
-			if (env.CLEANUP_WS_UNITTESTS.toBoolean()) {
-				cleanWs deleteDirs: true, notFailBuild: false
+			script {
+				if (env.CLEANUP_WS_UNITTESTS.toBoolean()) {
+					cleanWs deleteDirs: true, notFailBuild: false
+				}
 			}
 		}
 		/*