diff --git a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/linking/lazy/LazyLinkingResource.java b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/linking/lazy/LazyLinkingResource.java
index 75d6b8a63..ced84ca77 100644
--- a/plugins/org.eclipse.xtext/src/org/eclipse/xtext/linking/lazy/LazyLinkingResource.java
+++ b/plugins/org.eclipse.xtext/src/org/eclipse/xtext/linking/lazy/LazyLinkingResource.java
@@ -211,6 +211,9 @@ public class LazyLinkingResource extends XtextResource {
 		return super.getEObject(uriFragment);
 	}
 
+	/**
+	 * @since 2.1
+	 */
 	protected boolean isUnresolveableProxyCacheable(Triple<EObject, EReference, INode> triple) {
 		return true;
 	}