2 files changed, 3 insertions, 1 deletions
diff --git a/crypto/test/BouncyCastle.Crypto.Tests.csproj b/crypto/test/BouncyCastle.Crypto.Tests.csproj
index 9e9282f05..77a873a2a 100644
--- a/crypto/test/BouncyCastle.Crypto.Tests.csproj
+++ b/crypto/test/BouncyCastle.Crypto.Tests.csproj
@@ -5,7 +5,7 @@
     <IsPackable>false</IsPackable>
     <SignAssembly>false</SignAssembly>
     <EnableDefaultItems>false</EnableDefaultItems>
-    <NoWarn>1591</NoWarn>
+    <NoWarn>618;1591</NoWarn>
     <RootNamespace>Org.BouncyCastle</RootNamespace>
   </PropertyGroup>
 
diff --git a/crypto/test/src/math/test/BigIntegerTest.cs b/crypto/test/src/math/test/BigIntegerTest.cs
index f5973c197..8f477d684 100644
--- a/crypto/test/src/math/test/BigIntegerTest.cs
+++ b/crypto/test/src/math/test/BigIntegerTest.cs
@@ -773,11 +773,13 @@ namespace Org.BouncyCastle.Math.Tests
                 BigInteger x = new BigInteger(128, random);
                 object y;
 
+#pragma warning disable SYSLIB0011 // Type or member is obsolete
                 var formatter = new BinaryFormatter();
                 formatter.Serialize(buf, x);
 
                 buf.Position = 0;
                 y = formatter.Deserialize(buf);
+#pragma warning restore SYSLIB0011 // Type or member is obsolete
 
                 Assert.AreEqual(buf.Length, buf.Position);
                 Assert.AreEqual(x, y);