diff --git a/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/DiagramComposite.java b/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/DiagramComposite.java
index 7edcc47..c151e77 100644
--- a/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/DiagramComposite.java
+++ b/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/DiagramComposite.java
@@ -42,6 +42,9 @@
  * composite.
  * 
  * @since 0.10
+ * @experimental This API is in an experimental state and should be used by
+ *               clients only with care, as it not final and can be removed or
+ *               changed without prior notice!
  */
 public class DiagramComposite extends GraphicalComposite implements IDiagramContainerUI {
 
diff --git a/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/GraphicalComposite.java b/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/GraphicalComposite.java
index 3fd08e3..66d113a 100644
--- a/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/GraphicalComposite.java
+++ b/plugins/org.eclipse.graphiti.ui/src/org/eclipse/graphiti/ui/editor/GraphicalComposite.java
@@ -54,6 +54,9 @@
  * supports graphical editing.
  * 
  * @since 0.10
+ * @experimental This API is in an experimental state and should be used by
+ *               clients only with care, as it not final and can be removed or
+ *               changed without prior notice!
  */
 @SuppressWarnings("rawtypes")
 public abstract class GraphicalComposite extends Composite implements CommandStackListener,