diff --git a/lib/krb5/build_auth.c b/lib/krb5/build_auth.c
index 340fd43c8..4c0518922 100644
--- a/lib/krb5/build_auth.c
+++ b/lib/krb5/build_auth.c
@@ -39,6 +39,7 @@ krb5_build_authenticator (krb5_context context,
 
   memset (buf, 0, sizeof(buf));
   len = encode_Authenticator (buf + sizeof(buf) - 1, sizeof(buf), auth);
+  free (auth->crealm);
 
   ret = krb5_encrypt (context, buf + sizeof(buf) - len, len, &cred->session, result);