diff --git a/lib/jekyll/site.rb b/lib/jekyll/site.rb
index b892a31a..cbd7eba7 100644
--- a/lib/jekyll/site.rb
+++ b/lib/jekyll/site.rb
@@ -77,11 +77,10 @@ module Jekyll
               require f
             end
         end
-        self.gems.each do |gem|
-          require gem
-        end
       end
 
+      require_gems
+
       self.converters = instantiate_subclasses(Jekyll::Converter)
       self.generators = instantiate_subclasses(Jekyll::Generator)
     end
@@ -97,6 +96,18 @@ module Jekyll
       end
     end
 
+    def require_gems
+      self.gems.each do |gem|
+        if gem_whitelist.include?(gem) || !self.safe
+          require gem
+        end
+      end
+    end
+
+    def gem_whitelist
+      @gem_whitelist ||= []
+    end
+
     # Internal: Setup the plugin search path
     #
     # Returns an Array of plugin search paths