1 files changed, 1 insertions, 1 deletions

diff --git a/crypto/src/math/BigInteger.cs b/crypto/src/math/BigInteger.cs

index f31e2d5f2..ebeb78788 100644
--- a/crypto/src/math/BigInteger.cs
+++ b/crypto/src/math/BigInteger.cs
@@ -9,7 +9,7 @@ using Org.BouncyCastle.Utilities;
 
 namespace Org.BouncyCastle.Math
 {
-#if !(NETCF_1_0 || NETCF_2_0 || SILVERLIGHT)
+#if !(NETCF_1_0 || NETCF_2_0 || SILVERLIGHT || PORTABLE)
     [Serializable]
 #endif
     public class BigInteger