diff --git a/lib/ssh_data/public_key/rsa.rb b/lib/ssh_data/public_key/rsa.rb
index caf5de1..c104d9f 100644
--- a/lib/ssh_data/public_key/rsa.rb
+++ b/lib/ssh_data/public_key/rsa.rb
@@ -18,8 +18,8 @@ def initialize(algo:, e:, n:)
         @e = e
         @n = n
 
-        @openssl = OpenSSL::PKey::RSA.new(asn1.to_der)
-
+        @openssl = OpenSSL::PKey::RSA.new
+        @openssl.set_key(n, e, nil)
         super(algo: algo)
       end