diff --git a/features/responsive-image-tag.feature b/features/responsive-image-tag.feature
index ddad2f9..e8353fa 100644
--- a/features/responsive-image-tag.feature
+++ b/features/responsive-image-tag.feature
@@ -43,27 +43,26 @@ Feature: Jekyll responsive_image tag
           - width: 100
           - width: 200
       """
-    And I have a file "index.html" with "{% responsive_image path: assets/everybody-loves-jalapeño-pineapple-cornbread.png %}"
+    And I have a file "index.html" with "{% responsive_image path: assets/subdir/test.png %}"
     When I run Jekyll
-    Then I should see "<img alt=\"\" src=\"/assets/everybody-loves-jalapeño-pineapple-cornbread.png\"" in "_site/index.html"
-    And I should see "/assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png 100w" in "_site/index.html"
-    And I should see "/assets/resized/everybody-loves-jalapeño-pineapple-cornbread-200x100.png 200w" in "_site/index.html"
-    And I should see "/assets/everybody-loves-jalapeño-pineapple-cornbread.png 300w" in "_site/index.html"
-    And the file "assets/resized/everybody-loves-jalapeño-pineapple-cornbread-100x50.png" should exist
-    And the file "assets/resized/everybody-loves-jalapeño-pineapple-cornbread-200x100.png" should exist
+    Then I should see "<img alt=\"\" src=\"/assets/subdir/test.png\"" in "_site/index.html"
+    And I should see "/assets/resized/test-100x50.png 100w,/assets/resized/test-200x100.png 200w,/assets/subdir/test.png 300w" in "_site/index.html"
+
+    And the file "assets/resized/test-100x50.png" should exist
+    And the file "assets/resized/test-200x100.png" should exist
 
   Scenario: Overriding the template
     Given I have a responsive_image configuration with:
       """
         template: _includes/responsive-image.html
         sizes:
+          - width: 50
           - width: 100
-          - width: 200
-          - width: 300
+          - width: 150
       """
     And I have a file "index.html" with "{% responsive_image path: assets/everybody-loves-jalapeño-pineapple-cornbread.png template: _includes/custom-template.html %}"
     When I run Jekyll
-    Then I should see "[100, 200, 300]" in "_site/index.html"
+    Then I should see "[50, 100, 150]" in "_site/index.html"
 
   Scenario: Overriding the generated filenames
     Given I have a responsive_image configuration with:
diff --git a/features/step_definitions/jekyll_steps.rb b/features/step_definitions/jekyll_steps.rb
index 7284284..5ca4529 100644
--- a/features/step_definitions/jekyll_steps.rb
+++ b/features/step_definitions/jekyll_steps.rb
@@ -39,7 +39,8 @@ Given /^I have a file "(.+)" with "(.+)"$/ do |path, contents|
 end
 
 Then /^I should see "(.+)" in "(.*)"$/ do |text, file|
-  assert_match(Regexp.new(text), File.open(file).readlines.join)
+  contents = File.open(file).readlines.join
+  assert contents.inspect.include?(text), "Expected to find #{text.inspect} in #{contents.inspect}"
 end
 
 Then /^the file "(.+)" should exist$/ do |path|
diff --git a/features/test-site/_includes/responsive-image.html b/features/test-site/_includes/responsive-image.html
index 414d7f2..277fb39 100644
--- a/features/test-site/_includes/responsive-image.html
+++ b/features/test-site/_includes/responsive-image.html
@@ -1,4 +1 @@
-<img alt="{{ alt }}" src="/{{ path }}" title="{{ title }}" srcset="
-    {% for i in resized %}/{{ i.path }} {{ i.width }}w,{% endfor %}
-    /{{ original.path }} {{ original.width }}w
-">
+<img alt="{{ alt }}" src="/{{ path }}" title="{{ title }}" srcset="{% for i in resized %}/{{ i.path }} {{ i.width }}w,{% endfor %}/{{ original.path }} {{ original.width }}w">
diff --git a/lib/jekyll/responsive_image/common.rb b/lib/jekyll/responsive_image/common.rb
index 51cb0b2..60bc103 100644
--- a/lib/jekyll/responsive_image/common.rb
+++ b/lib/jekyll/responsive_image/common.rb
@@ -22,8 +22,8 @@ module Jekyll
           site = context.registers[:site]
           config = make_config(site)
 
-          source_image_path = site.in_source_dir(attributes['path'].to_s)
-          image = ImageProcessor.process(source_image_path, config)
+          absolute_image_path = site.in_source_dir(attributes['path'].to_s)
+          image = ImageProcessor.process(absolute_image_path, attributes['path'], config)
           attributes['original'] = image[:original]
           attributes['resized'] = image[:resized]
 
diff --git a/lib/jekyll/responsive_image/extra_image_generator.rb b/lib/jekyll/responsive_image/extra_image_generator.rb
index 566f9eb..70932fe 100644
--- a/lib/jekyll/responsive_image/extra_image_generator.rb
+++ b/lib/jekyll/responsive_image/extra_image_generator.rb
@@ -7,8 +7,10 @@ module Jekyll
         config = make_config(site)
 
         config['extra_images'].each do |pathspec|
-          Dir.glob(site.in_source_dir(pathspec)) do |path|
-            result = ImageProcessor.process(path, config)
+          Dir.glob(site.in_source_dir(pathspec)) do |image_path|
+            relative_image_path = image_path.sub(/^#{Regexp.escape(image_path)}/, '')
+
+            result = ImageProcessor.process(image_path, relative_image_path, config)
             result[:resized].each { |image| keep_resized_image!(site, image) }
           end
         end
diff --git a/lib/jekyll/responsive_image/image_processor.rb b/lib/jekyll/responsive_image/image_processor.rb
index afc7689..86a2b3a 100644
--- a/lib/jekyll/responsive_image/image_processor.rb
+++ b/lib/jekyll/responsive_image/image_processor.rb
@@ -3,20 +3,20 @@ module Jekyll
     class ImageProcessor
       include ResponsiveImage::Utils
 
-      def process(image_path, config)
-        raise SyntaxError.new("Invalid image path specified: #{image_path}") unless File.file?(image_path)
+      def process(absolute_image_path, relative_image_path, config)
+        raise SyntaxError.new("Invalid image path specified: #{absolute_image_path}") unless File.file?(absolute_image_path)
 
         resize_handler = ResizeHandler.new
-        img = Magick::Image::read(image_path).first
+        img = Magick::Image::read(absolute_image_path).first
 
         {
-          original: image_hash(config['base_path'], image_path, img.columns, img.rows),
+          original: image_hash(config['base_path'], relative_image_path, img.columns, img.rows),
           resized: resize_handler.resize_image(img, config),
         }
       end
 
-      def self.process(image_path, config)
-        self.new.process(image_path, config)
+      def self.process(absolute_image_path, relative_image_path, config)
+        self.new.process(absolute_image_path, relative_image_path, config)
       end
     end
   end