diff --git a/pkgs/development/python-modules/osc/default.nix b/pkgs/development/python-modules/osc/default.nix
index 3746d9df4685..e6ca2d065a88 100644
--- a/pkgs/development/python-modules/osc/default.nix
+++ b/pkgs/development/python-modules/osc/default.nix
@@ -8,6 +8,7 @@
   rpm,
   urllib3,
   keyring,
+  ruamel-yaml,
 }:
 
 buildPythonPackage rec {
@@ -31,6 +32,7 @@ buildPythonPackage rec {
     urllib3
     cryptography
     keyring
+    ruamel-yaml
   ];
 
   postInstall = ''