diff --git a/src/share/classes/sun/security/rsa/RSAKeyFactory.java b/src/share/classes/sun/security/rsa/RSAKeyFactory.java
index 54451256d5600afcc981cfb3cb50492ae739ff2e..021fa931829c208810ba0cd919eb3acb0dfb49b7 100644
--- a/src/share/classes/sun/security/rsa/RSAKeyFactory.java
+++ b/src/share/classes/sun/security/rsa/RSAKeyFactory.java
@@ -115,6 +115,9 @@ public class RSAKeyFactory extends KeyFactorySpi {
      * Used by RSASignature and RSACipher.
      */
     public static RSAKey toRSAKey(Key key) throws InvalidKeyException {
+        if (key == null) {
+            throw new InvalidKeyException("Key must not be null");
+        }
         if ((key instanceof RSAPrivateKeyImpl) ||
             (key instanceof RSAPrivateCrtKeyImpl) ||
             (key instanceof RSAPublicKeyImpl)) {