diff --git a/lib/rspec_api_documentation/views/markup_example.rb b/lib/rspec_api_documentation/views/markup_example.rb
index 70e0dc4a..b47729d9 100644
--- a/lib/rspec_api_documentation/views/markup_example.rb
+++ b/lib/rspec_api_documentation/views/markup_example.rb
@@ -19,7 +19,7 @@ def respond_to?(method, include_private = false)
       end
 
       def dirname
-        resource_name.downcase.gsub(/\s+/, '_').gsub(":", "_")
+        resource_name.to_s.downcase.gsub(/\s+/, '_').gsub(":", "_")
       end
 
       def filename
diff --git a/lib/rspec_api_documentation/writers/combined_text_writer.rb b/lib/rspec_api_documentation/writers/combined_text_writer.rb
index 454711a8..0d81df94 100644
--- a/lib/rspec_api_documentation/writers/combined_text_writer.rb
+++ b/lib/rspec_api_documentation/writers/combined_text_writer.rb
@@ -44,7 +44,7 @@ def initialize(example)
       end
 
       def resource_name
-        example.resource_name.downcase.gsub(/\s+/, '_')
+        example.resource_name.to_s.downcase.gsub(/\s+/, '_')
       end
 
       def description
diff --git a/lib/rspec_api_documentation/writers/json_writer.rb b/lib/rspec_api_documentation/writers/json_writer.rb
index 2ba099cb..e9b9db96 100644
--- a/lib/rspec_api_documentation/writers/json_writer.rb
+++ b/lib/rspec_api_documentation/writers/json_writer.rb
@@ -74,7 +74,7 @@ def respond_to?(method, include_private = false)
       end
 
       def dirname
-        resource_name.downcase.gsub(/\s+/, '_')
+        resource_name.to_s.downcase.gsub(/\s+/, '_')
       end
 
       def filename