diff --git a/lib/rubocop/cop/base.rb b/lib/rubocop/cop/base.rb
index 39cea5913e4e..d0c5dae9930b 100644
--- a/lib/rubocop/cop/base.rb
+++ b/lib/rubocop/cop/base.rb
@@ -481,6 +481,12 @@ def range_for_original(range)
           range.end_pos + @current_offset
         )
       end
+
+      # This experimental feature has been under consideration for a while.
+      # @api private
+      def lsp_mode?
+        ARGV.include?('--lsp')
+      end
     end
   end
 end
diff --git a/lib/rubocop/cop/lint/syntax.rb b/lib/rubocop/cop/lint/syntax.rb
index 457fac1c6e4f..f77c20fbe5e3 100644
--- a/lib/rubocop/cop/lint/syntax.rb
+++ b/lib/rubocop/cop/lint/syntax.rb
@@ -17,9 +17,12 @@ def on_other_file
         private
 
         def add_offense_from_diagnostic(diagnostic, ruby_version)
-          message =
-            "#{diagnostic.message}\n(Using Ruby #{ruby_version} parser; " \
-            'configure using `TargetRubyVersion` parameter, under `AllCops`)'
+          message = if lsp_mode?
+                      diagnostic.message
+                    else
+                      "#{diagnostic.message}\n(Using Ruby #{ruby_version} parser; " \
+                        'configure using `TargetRubyVersion` parameter, under `AllCops`)'
+                    end
           add_offense(diagnostic.location, message: message, severity: diagnostic.level)
         end
 
diff --git a/lib/rubocop/rspec/shared_contexts.rb b/lib/rubocop/rspec/shared_contexts.rb
index 562d5f5588f6..19aa69890210 100644
--- a/lib/rubocop/rspec/shared_contexts.rb
+++ b/lib/rubocop/rspec/shared_contexts.rb
@@ -128,6 +128,12 @@ def source_range(range, buffer: source_buffer)
   end
 end
 
+RSpec.shared_context 'lsp mode' do
+  before do
+    allow(cop).to receive(:lsp_mode?).and_return(true)
+  end
+end
+
 RSpec.shared_context 'ruby 2.0' do
   let(:ruby_version) { 2.0 }
 end
diff --git a/lib/rubocop/rspec/support.rb b/lib/rubocop/rspec/support.rb
index 7c8777f261e7..acad83989417 100644
--- a/lib/rubocop/rspec/support.rb
+++ b/lib/rubocop/rspec/support.rb
@@ -13,6 +13,7 @@
   config.include HostEnvironmentSimulatorHelper
   config.include_context 'config', :config
   config.include_context 'isolated environment', :isolated_environment
+  config.include_context 'lsp mode', :lsp_mode
   config.include_context 'maintain registry', :restore_registry
   config.include_context 'ruby 2.0', :ruby20
   config.include_context 'ruby 2.1', :ruby21
diff --git a/spec/rubocop/cop/lint/syntax_spec.rb b/spec/rubocop/cop/lint/syntax_spec.rb
index a3cc58b5316a..ca3e034fe6e0 100644
--- a/spec/rubocop/cop/lint/syntax_spec.rb
+++ b/spec/rubocop/cop/lint/syntax_spec.rb
@@ -50,6 +50,12 @@
           expect(offense.severity).to eq(:fatal)
         end
       end
+
+      context 'with `--lsp` option', :lsp_mode do
+        it 'does not include a configration information in the offense message' do
+          expect(offenses.first.message).to eq('unexpected token $end')
+        end
+      end
     end
 
     context 'with a parser error' do