diff --git a/lib/standard/lsp/routes.rb b/lib/standard/lsp/routes.rb
index b8bed922..796d5ae7 100644
--- a/lib/standard/lsp/routes.rb
+++ b/lib/standard/lsp/routes.rb
@@ -30,7 +30,8 @@ def for(name)
             diagnostic_provider: true,
             execute_command_provider: true,
             text_document_sync: Proto::Interface::TextDocumentSyncOptions.new(
-              change: Proto::Constant::TextDocumentSyncKind::FULL
+              change: Proto::Constant::TextDocumentSyncKind::FULL,
+              open_close: true
             )
           )
         ))
diff --git a/test/standard/runners/lsp_test.rb b/test/standard/runners/lsp_test.rb
index d6bf5d24..cc436280 100644
--- a/test/standard/runners/lsp_test.rb
+++ b/test/standard/runners/lsp_test.rb
@@ -16,7 +16,7 @@ def test_server_initializes_and_responds_with_proper_capabilities
     assert_equal msgs.first, {
       id: 2,
       result: {capabilities: {
-        textDocumentSync: {change: 1},
+        textDocumentSync: {openClose: true, change: 1},
         documentFormattingProvider: true,
         diagnosticProvider: true,
         executeCommandProvider: true