diff --git a/app/Main.hs b/app/Main.hs
index 042c948..3a63b4b 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -167,7 +167,7 @@ showByteHex :: Word8 -> String
 showByteHex = printf "      %02X"
 
 showByteBin :: Word8 -> String
-showByteBin = printf "%8b"
+showByteBin = printf "%08b"
 
 blockName :: Char -> Maybe String
 blockName c = UnicodeBlocks.blockName . UnicodeBlocks.blockDefinition <$> UnicodeBlocks.block c
diff --git a/nix/docker-image.nix b/nix/docker-image.nix
new file mode 100644
index 0000000..fc6f3b7
--- /dev/null
+++ b/nix/docker-image.nix
@@ -0,0 +1,9 @@
+let
+  pkgs = import ./pkgs.nix {};
+  utoy = import ../utoy.nix;
+in
+  pkgs.dockerTools.buildImage {
+    name = "git.pbrinkmeier.de/paul/utoy";
+    tag = "1.0";
+    config.Cmd = [ "${utoy}/bin/utoy" ];
+  }
diff --git a/utoy.cabal b/utoy.cabal
index 7de79bb..05bc3e4 100644
--- a/utoy.cabal
+++ b/utoy.cabal
@@ -14,7 +14,7 @@ license-file:   LICENSE
 build-type:     Simple
 extra-source-files:
     README.md
-    utoy.css
+    static/utoy.css
 
 source-repository head
   type: git