diff --git a/spec/oga/css/evaluator/ids_spec.rb b/spec/oga/css/evaluator/ids_spec.rb
new file mode 100644
index 0000000..cc4a17c
--- /dev/null
+++ b/spec/oga/css/evaluator/ids_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+describe 'CSS selector evaluation' do
+  context 'IDs' do
+    before do
+      @document = parse('<x id="foo" />')
+    end
+
+    example 'return a node set containing a node with a single ID' do
+      evaluate_css(@document, '#foo').should == @document.children
+    end
+
+    example 'return an empty node set for non matching IDs' do
+      evaluate_css(@document, '#bar').should == node_set
+    end
+  end
+end