diff --git a/lib/github_changelog_generator.rb b/lib/github_changelog_generator.rb
index 191d330..d2af44e 100755
--- a/lib/github_changelog_generator.rb
+++ b/lib/github_changelog_generator.rb
@@ -5,6 +5,7 @@ require "octokit"
 require "faraday-http-cache"
 require "logger"
 require "active_support"
+require "active_support/core_ext/object/blank"
 require "json"
 require "multi_json"
 require "benchmark"
diff --git a/lib/github_changelog_generator/generator/generator.rb b/lib/github_changelog_generator/generator/generator.rb
index 833e969..5e34a2b 100644
--- a/lib/github_changelog_generator/generator/generator.rb
+++ b/lib/github_changelog_generator/generator/generator.rb
@@ -36,16 +36,17 @@ module GitHubChangelogGenerator
       detect_actual_closed_dates(@issues + @pull_requests)
     end
 
-    # Encapsulate characters to make markdown look as expected.
+    ENCAPSULATED_CHARACTERS = %w(< > * _ \( \) [ ] #)
+
+    # Encapsulate characters to make Markdown look as expected.
     #
     # @param [String] string
     # @return [String] encapsulated input string
     def encapsulate_string(string)
-      string.gsub! '\\', '\\\\'
+      string = string.gsub('\\', '\\\\')
 
-      encpas_chars = %w(< > * _ \( \) [ ] #)
-      encpas_chars.each do |char|
-        string.gsub! char, "\\#{char}"
+      ENCAPSULATED_CHARACTERS.each do |char|
+        string = string.gsub(char, "\\#{char}")
       end
 
       string
diff --git a/spec/unit/generator/generator_generation_spec.rb b/spec/unit/generator/generator_generation_spec.rb
new file mode 100644
index 0000000..c849eda
--- /dev/null
+++ b/spec/unit/generator/generator_generation_spec.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module GitHubChangelogGenerator
+  describe Generator do
+    describe "#get_string_for_issue" do
+      let(:issue) do
+        { "title" => "Bug in code" }
+      end
+
+      it "formats an issue according to options" do
+        expect do
+          described_class.new.get_string_for_issue(issue)
+        end.not_to raise_error
+      end
+    end
+  end
+end