diff --git a/lib/jekyll/responsive_image/version.rb b/lib/jekyll/responsive_image/version.rb
index c7b1342..1cb7a3e 100644
--- a/lib/jekyll/responsive_image/version.rb
+++ b/lib/jekyll/responsive_image/version.rb
@@ -1,5 +1,5 @@
 module Jekyll
   class ResponsiveImage
-    VERSION = '0.18.0'.freeze
+    VERSION = '1.0.0.pre'.freeze
   end
 end