diff --git a/cl-sasl.nix b/cl-sasl.nix
index cd9e7a9..44c21ee 100644
--- a/cl-sasl.nix
+++ b/cl-sasl.nix
@@ -17,4 +17,7 @@ in buildLisp.library {
     "${cl-sasl-path}/plain.lisp"
     "${cl-sasl-path}/digest-md5.lisp"
   ];
+  deps = with pkgs.lispPackages; [
+    ironclad
+  ];
 }