diff --git a/pkgs/applications/science/logic/easycrypt/runtest.nix b/pkgs/applications/science/logic/easycrypt/runtest.nix
index 79a034b93693..c0d72d96e1d1 100644
--- a/pkgs/applications/science/logic/easycrypt/runtest.nix
+++ b/pkgs/applications/science/logic/easycrypt/runtest.nix
@@ -2,6 +2,7 @@
 
 python3Packages.buildPythonApplication rec {
   inherit (easycrypt) src version;
+  format = "other";
 
   pname = "easycrypt-runtest";