diff --git a/lib/google/apis/generator/helpers.rb b/lib/google/apis/generator/helpers.rb
index e57fb6cd9..64c6309ab 100644
--- a/lib/google/apis/generator/helpers.rb
+++ b/lib/google/apis/generator/helpers.rb
@@ -37,7 +37,9 @@ module Google
         # @param [String] name
         # @return [String] updated param name
         def normalize_param_name(name)
-          name = ActiveSupport::Inflector.underscore(name.gsub(/\W/, '_'))
+          name = name.gsub(/\W/, '_')
+          name = name.gsub(/IPv4/, 'Ipv4')
+          name = ActiveSupport::Inflector.underscore(name)
           if reserved?(name)
             logger.warn { sprintf('Found reserved keyword \'%1$s\'', name) }
             name += '_'