diff --git a/pkgs/development/python-modules/ripe-atlas-cousteau/default.nix b/pkgs/development/python-modules/ripe-atlas-cousteau/default.nix
index 730560a00821..34b22109d8e4 100644
--- a/pkgs/development/python-modules/ripe-atlas-cousteau/default.nix
+++ b/pkgs/development/python-modules/ripe-atlas-cousteau/default.nix
@@ -33,7 +33,7 @@ buildPythonPackage rec {
     python-dateutil
     requests
     python-socketio
-  ];
+  ] ++ python-socketio.optional-dependencies.client;
 
   checkInputs = [
     pytestCheckHook