diff --git a/.image_optim.yml b/.image_optim.yml
index e0416a670d..ba5d735b27 100644
--- a/.image_optim.yml
+++ b/.image_optim.yml
@@ -1,10 +1,11 @@
 skip_missing_workers: true
-allow_lossy: false
+allow_lossy: true
 # PNG
 advpng: false
 optipng: false
 pngcrush: false
-pngout: true
-pngquant: false
+pngout: false
+pngquant:
+  quality: !ruby/range 75..90
 # JPG
 jpegrecompress: false
diff --git a/lib/version.rb b/lib/version.rb
index b16d4c6d61..5fc644b4b6 100644
--- a/lib/version.rb
+++ b/lib/version.rb
@@ -5,7 +5,7 @@ module Discourse
       MAJOR = 1
       MINOR = 4
       TINY  = 0
-      PRE   = 'beta5'
+      PRE   = 'beta6'
 
       STRING = [MAJOR, MINOR, TINY, PRE].compact.join('.')
     end