1 files changed, 1 insertions, 2 deletions
diff --git a/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs b/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
index d986e7f01..6631657f4 100644
--- a/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
+++ b/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
@@ -24,8 +24,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
         */
         protected override ECPoint MultiplyPositive(ECPoint point, BigInteger k)
         {
-            AbstractF2mPoint p = point as AbstractF2mPoint;
-            if (p == null)
+            if (!(point is AbstractF2mPoint p))
                 throw new ArgumentException("Only AbstractF2mPoint can be used in WTauNafMultiplier");
 
             AbstractF2mCurve curve = (AbstractF2mCurve)p.Curve;