2 files changed, 3 insertions, 1 deletions
diff --git a/crypto/src/asn1/DerOutputStream.cs b/crypto/src/asn1/DerOutputStream.cs
index f95d123f9..c03d9dc11 100644
--- a/crypto/src/asn1/DerOutputStream.cs
+++ b/crypto/src/asn1/DerOutputStream.cs
@@ -1,7 +1,7 @@
 using System;
 using System.IO;
 
-using Org.BouncyCastle.Asn1.Utilities;
+using Org.BouncyCastle.Utilities.IO;
 
 namespace Org.BouncyCastle.Asn1
 {
diff --git a/crypto/src/asn1/util/FilterStream.cs b/crypto/src/asn1/util/FilterStream.cs
index 2b0494b78..980e7f176 100644
--- a/crypto/src/asn1/util/FilterStream.cs
+++ b/crypto/src/asn1/util/FilterStream.cs
@@ -3,8 +3,10 @@ using System.IO;
 
 namespace Org.BouncyCastle.Asn1.Utilities
 {
+    [Obsolete("Use Org.BouncyCastle.Utilities.IO.FilterStream")]
     public class FilterStream : Stream
     {
+        [Obsolete("Use Org.BouncyCastle.Utilities.IO.FilterStream")]
         public FilterStream(Stream s)
         {
             this.s = s;