diff --git a/lib/rbs/definition.rb b/lib/rbs/definition.rb
index da3af8331..f92e6fd03 100644
--- a/lib/rbs/definition.rb
+++ b/lib/rbs/definition.rb
@@ -120,7 +120,7 @@ def method_types
       end
 
       def comments
-        @comments ||= _ = defs.map(&:comment).compact
+        @comments ||= defs.map(&:comment).compact.uniq
       end
 
       def annotations
diff --git a/test/rbs/definition_builder_test.rb b/test/rbs/definition_builder_test.rb
index 68edd74b0..7b0ef0df2 100644
--- a/test/rbs/definition_builder_test.rb
+++ b/test/rbs/definition_builder_test.rb
@@ -454,6 +454,27 @@ def foo: (String) -> String | ...
     end
   end
 
+  def test_build_comment_dedup
+    SignatureManager.new do |manager|
+      manager.files.merge!(Pathname("foo.rbs") => <<-EOF)
+class Hello
+  # doc1
+  def foo: () -> String
+         | (Integer) -> String
+end
+      EOF
+      manager.build do |env|
+        builder = DefinitionBuilder.new(env: env)
+
+        builder.build_instance(type_name("::Hello")).tap do |definition|
+          foo = definition.methods[:foo]
+
+          assert_equal 1, foo.comments.size
+        end
+      end
+    end
+  end
+
   def test_build_instance_method_variance
     SignatureManager.new do |manager|
       manager.files.merge!(Pathname("foo.rbs") => <<-EOF)