diff --git a/interpreter/LispProcedure.cs b/interpreter/LispProcedure.cs
index 6c29359..96066e2 100644
--- a/interpreter/LispProcedure.cs
+++ b/interpreter/LispProcedure.cs
@@ -1,5 +1,3 @@
-using System.DirectoryServices;
-
 namespace KumiScript.Interpreter
 {
     public class LispProcedure : Procedure
@@ -43,4 +41,4 @@ namespace KumiScript.Interpreter
             return string.Concat("λ(", string.Join(' ', _parameters), ")");
         }
     }
-}
\ No newline at end of file
+}