diff --git a/.image_optim.yml b/.image_optim.yml
index c7196cbb2..ba5d735b2 100644
--- a/.image_optim.yml
+++ b/.image_optim.yml
@@ -6,6 +6,6 @@ optipng: false
 pngcrush: false
 pngout: false
 pngquant:
-  quality: !ruby/range 10..90
+  quality: !ruby/range 75..90
 # JPG
 jpegrecompress: false