diff --git a/lib/oga/xpath/compiler.rb b/lib/oga/xpath/compiler.rb
index 64e24df..c2c60be 100644
--- a/lib/oga/xpath/compiler.rb
+++ b/lib/oga/xpath/compiler.rb
@@ -223,8 +223,10 @@ module Oga
       def on_axis_descendant(ast, input)
         node = node_literal
 
-        input.each_node.add_block(node) do
-          process(ast, node).if_true { yield node }
+        document_or_node(input).if_true do
+          input.each_node.add_block(node) do
+            process(ast, node).if_true { yield node }
+          end
         end
       end
 
diff --git a/spec/oga/xpath/compiler/axes/descendant_spec.rb b/spec/oga/xpath/compiler/axes/descendant_spec.rb
index ff0196d..3d34da2 100644
--- a/spec/oga/xpath/compiler/axes/descendant_spec.rb
+++ b/spec/oga/xpath/compiler/axes/descendant_spec.rb
@@ -1,33 +1,60 @@
 require 'spec_helper'
 
 describe Oga::XPath::Compiler do
-  describe 'descendant axis' do
-    before do
-      @document = parse('<a><b><c></c></b><a></a></a>')
+  before do
+    @document = parse('<a foo="bar"><b><c></c></b><a></a></a>')
 
-      @a1 = @document.children[0]
-      @a2 = @a1.children[-1]
-      @c1 = @a1.children[0].children[0]
+    @a1 = @document.children[0]
+    @a2 = @a1.children[-1]
+    @b1 = @a1.children[0]
+    @c1 = @b1.children[0]
+  end
+
+  describe 'relative to a document' do
+    describe 'descendant::a' do
+      it 'returns a NodeSet' do
+        evaluate_xpath(@document).should == node_set(@a1, @a2)
+      end
     end
 
-    it 'returns a node set containing a direct descendant' do
-      evaluate_xpath(@document, 'descendant::a').should == node_set(@a1, @a2)
+    describe 'descendant::c' do
+      it 'returns a NodeSet' do
+        evaluate_xpath(@document).should == node_set(@c1)
+      end
     end
 
-    it 'returns a node set containing a nested descendant' do
-      evaluate_xpath(@document, 'descendant::c').should == node_set(@c1)
+    describe 'a/descendant::a' do
+      it 'returns a NodeSet' do
+        evaluate_xpath(@document).should == node_set(@a2)
+      end
     end
 
-    it 'returns a node set containing a descendant relative to a node' do
-      evaluate_xpath(@document, 'a/descendant::a').should == node_set(@a2)
+    describe 'descendant::a[1]' do
+      it 'returns a NodeSet' do
+        evaluate_xpath(@document).should == node_set(@a1)
+      end
     end
 
-    it 'returns a node set containing the first descendant' do
-      evaluate_xpath(@document, 'descendant::a[1]').should == node_set(@a1)
+    describe 'a/b/c/descendant::c' do
+      it 'returns an empty NodeSet' do
+        evaluate_xpath(@document).should == node_set
+      end
     end
+  end
 
-    it 'returns an empty node set for non existing descendants' do
-      evaluate_xpath(@document, 'a/b/c/descendant::c').should == node_set
+  describe 'relative to an element' do
+    describe 'descendant::b' do
+      it 'returns a NodeSet' do
+        evaluate_xpath(@a1).should == node_set(@b1)
+      end
+    end
+  end
+
+  describe 'relative to an attribute' do
+    describe 'descendant::b' do
+      it 'returns an empty NodeSet' do
+        evaluate_xpath(@a1.attribute('foo')).should == node_set
+      end
     end
   end
 end