diff --git a/Rakefile b/Rakefile
index f8bd96087..8df39bde5 100644
--- a/Rakefile
+++ b/Rakefile
@@ -11,6 +11,12 @@ Rake::TestTask.new(:test) do |t|
   t.test_files = FileList["test/**/*_test.rb", "lib/ruby_indexer/test/**/*_test.rb"].exclude("test/fixtures/prism/**/*")
 end
 
+Rake::TestTask.new(:test_indexer) do |t|
+  t.libs << "test"
+  t.libs << "lib"
+  t.test_files = FileList["lib/ruby_indexer/test/**/*_test.rb"].exclude("test/fixtures/prism/**/*")
+end
+
 RDoc::Task.new do |rdoc|
   rdoc.main = "README.md"
   rdoc.title = "Ruby LSP documentation"
diff --git a/lib/ruby_indexer/lib/ruby_indexer/declaration_listener.rb b/lib/ruby_indexer/lib/ruby_indexer/declaration_listener.rb
index 930c4180e..a4aa572d7 100644
--- a/lib/ruby_indexer/lib/ruby_indexer/declaration_listener.rb
+++ b/lib/ruby_indexer/lib/ruby_indexer/declaration_listener.rb
@@ -523,7 +523,7 @@ def add_constant(node, name, value = nil)
 
     sig { params(node: Prism::Node).returns(String) }
     def collect_comments(node)
-      comments = []
+      comments = +""
 
       start_line = node.location.start_line - 1
       start_line -= 1 unless @comments_by_line.key?(start_line)
@@ -541,10 +541,11 @@ def collect_comments(node)
 
         comment_content.delete_prefix!("#")
         comment_content.delete_prefix!(" ")
-        comments.prepend(comment_content)
+        comments.prepend("#{comment_content}\n")
       end
 
-      comments.join("\n")
+      comments.chomp!
+      comments
     end
 
     sig { params(name: String).returns(String) }