diff --git a/geocoder.gemspec b/geocoder.gemspec
index ed6955a26..505dea33f 100644
--- a/geocoder.gemspec
+++ b/geocoder.gemspec
@@ -22,4 +22,6 @@ Gem::Specification.new do |s|
     'source_code_uri' => 'https://github.com/alexreisner/geocoder',
     'changelog_uri'   => 'https://github.com/alexreisner/geocoder/blob/master/CHANGELOG.md'
   }
+  s.add_dependency("base64", ">= 0.1.0") # for :google_premier lookup
+  s.add_dependency("csv", ">= 3.0.0") # for :maxmind lookup
 end