diff --git a/examples/plantuml/.gitignore b/examples/plantuml/.gitignore
new file mode 100644
index 00000000..930e968d
--- /dev/null
+++ b/examples/plantuml/.gitignore
@@ -0,0 +1,2 @@
+dist
+dist2
\ No newline at end of file
diff --git a/plantuml-plugin/src/test/java/io/freefair/gradle/plugins/plantuml/PlantumlPluginTest.java b/plantuml-plugin/src/test/java/io/freefair/gradle/plugins/plantuml/PlantumlPluginTest.java
index 3d2e2a1b..e98caba9 100644
--- a/plantuml-plugin/src/test/java/io/freefair/gradle/plugins/plantuml/PlantumlPluginTest.java
+++ b/plantuml-plugin/src/test/java/io/freefair/gradle/plugins/plantuml/PlantumlPluginTest.java
@@ -39,6 +39,21 @@ void execute() {
 
         task.source(getClass().getClassLoader().getResource("puml-files").getPath());
 
+        task.getDeleteOutputBeforeBuild().set(true);
+
+        assertThrows(UnsupportedOperationException.class, task::execute);
+    }
+
+    @Test
+    void executeWithoutDelete() {
+        project.getPlugins().apply(PlantumlPlugin.class);
+
+        PlantumlTask task = project.getTasks().withType(PlantumlTask.class).getByName("plantUml");
+
+        task.source(getClass().getClassLoader().getResource("puml-files").getPath());
+
+        task.getDeleteOutputBeforeBuild().set(false);
+
         assertThrows(UnsupportedOperationException.class, task::execute);
     }