diff --git a/lib/geminabox.rb b/lib/geminabox.rb
index ef242a75..aba6e09c 100644
--- a/lib/geminabox.rb
+++ b/lib/geminabox.rb
@@ -54,7 +54,7 @@ def fixup_bundler_rubygems!
 
   # Return a list of versions of gem 'gem_name' with the dependencies of each version.
   def gem_dependencies(gem_name)
-    dependency_cache.cache(gem_name) do
+    dependency_cache.marshal_cache(gem_name) do
       load_gems.select {|gem| gem_name == gem.name }.map do |gem|
         spec = spec_for(gem.name, gem.number)
         {
diff --git a/lib/geminabox/disk_cache.rb b/lib/geminabox/disk_cache.rb
index d64c4f86..2f1c76ab 100644
--- a/lib/geminabox/disk_cache.rb
+++ b/lib/geminabox/disk_cache.rb
@@ -23,6 +23,11 @@ def cache(key)
     read(key_hash) || write(key_hash, yield)
   end
 
+  def marshal_cache(key)
+    key_hash = key_hash(key)
+    marshal_read(key_hash) || marshal_write(key_hash, yield)
+  end
+
 protected
 
   def ensure_dir_exists!
@@ -38,16 +43,30 @@ def path(key_hash)
   end
 
   def read(key_hash)
+    read_int(key_hash) { |path| File.read(path) }
+  end
+
+  def marshal_read(key_hash)
+    read_int(key_hash) { |path| Marshal.load(File.open(path)) }
+  end
+
+  def read_int(key_hash)
     path = path(key_hash)
-    File.read(path) if File.exists?(path)
+    yield(path) if File.exists?(path)
   end
 
   def write(key_hash, value)
-    path = path(key_hash)
-    File.open(path, 'wb'){|f|
-      f << value
-    }
+    write_int(key_hash) { |f| f << value }
+    value
+  end
+
+  def marshal_write(key_hash, value)
+    write_int(key_hash) { |f| Marshal.dump(value, f) }
     value
   end
 
+  def write_int(key_hash)
+    File.open(path(key_hash), 'wb') { |f| yield(f) }
+  end
+
 end