diff --git a/lib/oga/xpath/evaluator.rb b/lib/oga/xpath/evaluator.rb
index 6065c54..b0402ce 100644
--- a/lib/oga/xpath/evaluator.rb
+++ b/lib/oga/xpath/evaluator.rb
@@ -550,7 +550,9 @@ module Oga
         nodes = XML::NodeSet.new
 
         context.each do |node|
-          nodes << node if node.is_a?(XML::Node)
+          if node.is_a?(XML::Node) or node.is_a?(XML::Document)
+            nodes << node
+          end
         end
 
         return nodes
diff --git a/spec/oga/xpath/evaluator/axes/self_spec.rb b/spec/oga/xpath/evaluator/axes/self_spec.rb
index b499ce9..85eb0e8 100644
--- a/spec/oga/xpath/evaluator/axes/self_spec.rb
+++ b/spec/oga/xpath/evaluator/axes/self_spec.rb
@@ -74,5 +74,17 @@ describe Oga::XPath::Evaluator do
         @set[0].should == @document.children[0].children[1]
       end
     end
+
+    context 'matching the document itself' do
+      before do
+        @set = @evaluator.evaluate('self::node()')
+      end
+
+      it_behaves_like :node_set, :length => 1
+
+      example 'return the document itself' do
+        @set[0].is_a?(Oga::XML::Document).should == true
+      end
+    end
   end
 end