diff --git a/pkgs/tools/compression/zopfli/default.nix b/pkgs/tools/compression/zopfli/default.nix
index 2c844cffc21b..8d8813e2eda4 100644
--- a/pkgs/tools/compression/zopfli/default.nix
+++ b/pkgs/tools/compression/zopfli/default.nix
@@ -34,6 +34,7 @@ stdenv.mkDerivation rec {
     '';
     platforms = platforms.unix;
     license = licenses.asl20;
+    mainProgram = "zopfli";
     maintainers = with maintainers; [ bobvanderlinden edef ];
   };
 }