diff --git a/lib/syntax_tree/cli.rb b/lib/syntax_tree/cli.rb
index f2616c87..a9d1fd7a 100644
--- a/lib/syntax_tree/cli.rb
+++ b/lib/syntax_tree/cli.rb
@@ -593,7 +593,8 @@ def run(argv)
           when "j", "json"
             Json.new(options)
           when "lsp"
-            LanguageServer.new(print_width: options.print_width).run
+            LanguageServer.new(ignore_files: options.ignore_files,
+print_width: options.print_width).run
             return 0
           when "m", "match"
             Match.new(options)
diff --git a/lib/syntax_tree/language_server.rb b/lib/syntax_tree/language_server.rb
index 6ec81030..4db802bc 100644
--- a/lib/syntax_tree/language_server.rb
+++ b/lib/syntax_tree/language_server.rb
@@ -215,10 +215,12 @@ def self.[](value)
     attr_reader :input, :output, :print_width
 
     def initialize(
+      ignore_files: [],
       input: $stdin,
       output: $stdout,
       print_width: DEFAULT_PRINT_WIDTH
     )
+      @ignore_files = ignore_files
       @input = input.binmode
       @output = output.binmode
       @print_width = print_width
@@ -255,8 +257,12 @@ def run
           store.delete(request.dig(:params, :textDocument, :uri))
         when Request[method: "textDocument/formatting", id: :any, params: { textDocument: { uri: :any } }]
           uri = request.dig(:params, :textDocument, :uri)
+          filepath = uri.split("///").last
+          ignore = @ignore_files.any? do |glob|
+            File.fnmatch(glob, filepath)
+          end
           contents = store[uri]
-          write(id: request[:id], result: contents ? format(contents, uri.split(".").last) : nil)
+          write(id: request[:id], result: contents && !ignore ? format(contents, uri.split(".").last) : nil)
         when Request[method: "textDocument/inlayHint", id: :any, params: { textDocument: { uri: :any } }]
           uri = request.dig(:params, :textDocument, :uri)
           contents = store[uri]
diff --git a/test/language_server_test.rb b/test/language_server_test.rb
index f5a6ca57..7b6dc22c 100644
--- a/test/language_server_test.rb
+++ b/test/language_server_test.rb
@@ -151,6 +151,24 @@ def test_formatting
       assert_equal("class Bar\nend\n", responses.dig(1, :result, 0, :newText))
     end
 
+    def test_formatting_ignore
+      responses = run_server([
+        Initialize.new(1),
+        TextDocumentDidOpen.new("file:///path/to/file.rb", "class Foo; end"),
+        TextDocumentFormatting.new(2, "file:///path/to/file.rb"),
+        Shutdown.new(3)
+      ], ignore_files: ["path/**/*.rb"])
+
+      shape = LanguageServer::Request[[
+        { id: 1, result: { capabilities: Hash } },
+        { id: 2, result: :any },
+        { id: 3, result: {} }
+      ]]
+
+      assert_operator(shape, :===, responses)
+      assert_nil(responses.dig(1, :result))
+    end
+
     def test_formatting_failure
       responses = run_server([
         Initialize.new(1),
@@ -322,11 +340,12 @@ def read(content)
       end
     end
 
-    def run_server(messages, print_width: DEFAULT_PRINT_WIDTH)
+    def run_server(messages, ignore_files: [], print_width: DEFAULT_PRINT_WIDTH)
       input = StringIO.new(messages.map { |message| write(message) }.join)
       output = StringIO.new
 
       LanguageServer.new(
+        ignore_files: ignore_files,
         input: input,
         output: output,
         print_width: print_width