diff --git a/pkgs/os-specific/linux/iotop/default.nix b/pkgs/os-specific/linux/iotop/default.nix
index 0376ff1a55ec..41647a2378e4 100644
--- a/pkgs/os-specific/linux/iotop/default.nix
+++ b/pkgs/os-specific/linux/iotop/default.nix
@@ -22,6 +22,7 @@ python3Packages.buildPythonApplication rec {
     description = "A tool to find out the processes doing the most IO";
     homepage = "http://guichaz.free.fr/iotop";
     license = licenses.gpl2;
+    mainProgram = "iotop";
     maintainers = [ maintainers.raskin ];
     platforms = platforms.linux;
   };