1 files changed, 9 insertions, 2 deletions
diff --git a/crypto/src/crypto/signers/X931Signer.cs b/crypto/src/crypto/signers/X931Signer.cs
index 9db4e1642..c185eacfd 100644
--- a/crypto/src/crypto/signers/X931Signer.cs
+++ b/crypto/src/crypto/signers/X931Signer.cs
@@ -71,9 +71,16 @@ namespace Org.BouncyCastle.Crypto.Signers
 
         public virtual void Init(bool forSigning, ICipherParameters parameters)
         {
-            kParam = (RsaKeyParameters)parameters;
+            if (parameters is ParametersWithRandom withRandom)
+            {
+                kParam = (RsaKeyParameters)withRandom.Parameters;
+            }
+            else
+            {
+                kParam = (RsaKeyParameters)parameters;
+            }
 
-            cipher.Init(forSigning, kParam);
+            cipher.Init(forSigning, parameters);
 
             keyBits = kParam.Modulus.BitLength;