diff --git a/spec/oga/xpath/evaluator/types/float_spec.rb b/spec/oga/xpath/evaluator/types/float_spec.rb
index edd4077..e0e1f76 100644
--- a/spec/oga/xpath/evaluator/types/float_spec.rb
+++ b/spec/oga/xpath/evaluator/types/float_spec.rb
@@ -3,20 +3,19 @@ require 'spec_helper'
 describe Oga::XPath::Evaluator do
   context 'float types' do
     before do
-      document   = parse('<a></a>')
-      @evaluator = described_class.new(document)
+      @document = parse('')
     end
 
     example 'return a float' do
-      @evaluator.evaluate('1.2').should == 1.2
+      evaluate_xpath(@document, '1.2').should == 1.2
     end
 
     example 'return a negative float' do
-      @evaluator.evaluate('-1.2').should == -1.2
+      evaluate_xpath(@document, '-1.2').should == -1.2
     end
 
     example 'return floats as a Float' do
-      @evaluator.evaluate('1.2').is_a?(Float).should == true
+      evaluate_xpath(@document, '1.2').is_a?(Float).should == true
     end
   end
 end
diff --git a/spec/oga/xpath/evaluator/types/int_spec.rb b/spec/oga/xpath/evaluator/types/int_spec.rb
index 35364c3..cd0666b 100644
--- a/spec/oga/xpath/evaluator/types/int_spec.rb
+++ b/spec/oga/xpath/evaluator/types/int_spec.rb
@@ -3,20 +3,19 @@ require 'spec_helper'
 describe Oga::XPath::Evaluator do
   context 'integer types' do
     before do
-      document   = parse('<a></a>')
-      @evaluator = described_class.new(document)
+      @document = parse('')
     end
 
     example 'return an integer' do
-      @evaluator.evaluate('1').should == 1
+      evaluate_xpath(@document, '1').should == 1
     end
 
     example 'return a negative integer' do
-      @evaluator.evaluate('-2').should == -2
+      evaluate_xpath(@document, '-2').should == -2
     end
 
     example 'return integers as a Float' do
-      @evaluator.evaluate('1').is_a?(Float).should == true
+      evaluate_xpath(@document, '1').is_a?(Float).should == true
     end
   end
 end
diff --git a/spec/oga/xpath/evaluator/types/string_spec.rb b/spec/oga/xpath/evaluator/types/string_spec.rb
index f310350..5f27788 100644
--- a/spec/oga/xpath/evaluator/types/string_spec.rb
+++ b/spec/oga/xpath/evaluator/types/string_spec.rb
@@ -3,13 +3,11 @@ require 'spec_helper'
 describe Oga::XPath::Evaluator do
   context 'string types' do
     before do
-      document  = parse('<a></a>')
-      evaluator = described_class.new(document)
-      @string   = evaluator.evaluate('"foo"')
+      @document = parse('')
     end
 
     example 'return the literal string' do
-      @string.should == 'foo'
+      evaluate_xpath(@document, '"foo"').should == 'foo'
     end
   end
 end