diff --git a/org.eclipse.lsp4e.tests.mock/src/org/eclipse/lsp4e/tests/mock/MockLanguageServer.java b/org.eclipse.lsp4e.tests.mock/src/org/eclipse/lsp4e/tests/mock/MockLanguageServer.java
index 0d467a825..ff4f4bd8c 100644
--- a/org.eclipse.lsp4e.tests.mock/src/org/eclipse/lsp4e/tests/mock/MockLanguageServer.java
+++ b/org.eclipse.lsp4e.tests.mock/src/org/eclipse/lsp4e/tests/mock/MockLanguageServer.java
@@ -76,7 +76,7 @@
 import org.eclipse.lsp4j.services.LanguageServer;
 import org.eclipse.lsp4j.services.NotebookDocumentService;
 
-public final class MockLanguageServer implements LanguageServer {
+public class MockLanguageServer implements LanguageServer {
 
 	/**
 	 * This command will be reported on initialization to be supported for execution