1 files changed, 4 insertions, 1 deletions
diff --git a/ext/openssl/ossl_bn.c b/ext/openssl/ossl_bn.c
index 6f0064e966..6493e051e9 100644
--- a/ext/openssl/ossl_bn.c
+++ b/ext/openssl/ossl_bn.c
@@ -173,7 +173,6 @@ ossl_bn_alloc(VALUE klass)
 
 /*
  * call-seq:
- *    OpenSSL::BN.new => aBN
  *    OpenSSL::BN.new(bn) => aBN
  *    OpenSSL::BN.new(integer) => aBN
  *    OpenSSL::BN.new(string) => aBN
@@ -193,6 +192,10 @@ ossl_bn_initialize(int argc, VALUE *argv, VALUE self)
 	base = NUM2INT(bs);
     }
 
+    if (NIL_P(str)) {
+        ossl_raise(rb_eArgError, "invalid argument");
+    }
+
     if (RB_INTEGER_TYPE_P(str)) {
 	GetBN(self, bn);
 	integer_to_bnptr(str, bn);