diff --git a/src/PhoneNumbers/ParseException.cs b/src/PhoneNumbers/ParseException.cs
index 87513a67..64c13a8f 100644
--- a/src/PhoneNumbers/ParseException.cs
+++ b/src/PhoneNumbers/ParseException.cs
@@ -1,5 +1,3 @@
-using System.Runtime.Serialization;
-
 namespace PhoneNumbers;
 
 /// <summary>