diff --git a/lib/jekyll-gallery-generator.rb b/lib/jekyll-gallery-generator.rb
index 0e77769..a5ad76f 100644
--- a/lib/jekyll-gallery-generator.rb
+++ b/lib/jekyll-gallery-generator.rb
@@ -7,6 +7,12 @@
 
 $image_extensions = [".png", ".jpg", ".jpeg", ".gif", ".bmp"]
 
+unless File.respond_to?(:exists?)
+  class << File
+    alias_method :exists?, :exist?
+  end
+end
+
 module Jekyll
   class GalleryImage
     include Comparable