diff --git a/bindings/mruby/README.md b/bindings/mruby/README.md
index 59949fd4..29284c73 100644
--- a/bindings/mruby/README.md
+++ b/bindings/mruby/README.md
@@ -19,7 +19,8 @@ MRuby::Build.new do |conf|
   # ...
   conf.gem github: 'tailix/libkernaux',
            path: 'bindings/mruby',
-           branch: 'v0.4.0'
+           branch: 'v0.4.0',
+           checksum_hash: 'e488eed240ec9cf238d17948bd8431fa93190293'
   # ...
 end
 ```
diff --git a/sha256sums.txt b/sha256sums.txt
index a7cf3462..ae801931 100644
--- a/sha256sums.txt
+++ b/sha256sums.txt
@@ -1,3 +1,8 @@
+893292882e0b658d92e104dc0d2974d61daca60efdf9fdf80996c3db54b0cab2  libkernaux-0.4.0.tar.gz
+eb27d72d658f87638998cdb0056018edd49cc8f1144e23a1e00f7921a6bbd5b2  kernaux-0.4.0.crate
+ee0d63d1f86113f3f652427b908da27fda7be496b5bdbba9947977891b2e50ef  kernaux-sys-0.4.0.crate
+2c765894b10830abc5945b003d465515fb28b964f1e2f7cdd5594bbf1cdbce97  kernaux-0.4.0.gem
+#
 6887939c01b65a4e864d47f103a06a6ad1639f4bffaa5582c95252c4646c8d2a  libkernaux-0.3.0.tar.gz
 564e5a58a854dd6b2b4e212ebac9c76a099971a2fa95324916de07b67f46934c  kernaux-0.3.0.crate
 1fddd0383dcce818273f305fffd0c7153d3772fcaf78dae38c30dae4f0960a25  kernaux-sys-0.3.0.crate