diff --git a/default.nix b/default.nix
index 4eea08f..7f6b503 100644
--- a/default.nix
+++ b/default.nix
@@ -12,6 +12,7 @@ in pkgs.stdenv.mkDerivation {
     pkgs.nodePackages.html-minifier
     pkgs.nodePackages.clean-css-cli
     pkgs.nodePackages.uglify-js
+    pkgs.pngcrush
   ];
   buildPhase = ''
     zola build
@@ -41,6 +42,9 @@ in pkgs.stdenv.mkDerivation {
       --file-ext html \
       --input-dir public \
       --output-dir public
+
+    echo "compressing images"
+    find public -type f -name '*.png' | xargs -n 1 pngcrush -ow -brute
   '';
 
   installPhase = ''
diff --git a/shell.nix b/shell.nix
index 56add81..4bcf904 100644
--- a/shell.nix
+++ b/shell.nix
@@ -7,5 +7,5 @@ let
 in with nixpkgs;
 stdenv.mkDerivation {
   name = "bytes.zone";
-  buildInputs = [ niv.niv git zola pa11y.pa11y ];
+  buildInputs = [ niv.niv git zola pa11y.pa11y pngcrush ];
 }