diff --git a/pkgs/data/icons/maia-icon-theme/default.nix b/pkgs/data/icons/maia-icon-theme/default.nix
index fbde3a428c0f..ee539981fbca 100644
--- a/pkgs/data/icons/maia-icon-theme/default.nix
+++ b/pkgs/data/icons/maia-icon-theme/default.nix
@@ -27,7 +27,7 @@ stdenv.mkDerivation {
 
   dontDropIconThemeCache = true;
 
-  postFixup = ''
+  postInstall = ''
     for theme in $out/share/icons/*; do
       gtk-update-icon-cache $theme
     done