diff --git a/wolfcrypt/src/rsa.c b/wolfcrypt/src/rsa.c
index 78c0c9ec4..29275e101 100644
--- a/wolfcrypt/src/rsa.c
+++ b/wolfcrypt/src/rsa.c
@@ -2593,7 +2593,7 @@ static int RsaFunctionPrivate(mp_int* tmp, RsaKey* key, WC_RNG* rng)
     }
 #else
     if (ret == 0 && (mp_iszero(&key->p) || mp_iszero(&key->q) ||
-            mp_iszero(&key->dP) || mp_iszero(&key->dQ))) {
+            mp_iszero(&key->dP) || mp_iszero(&key->dQ) || mp_iszero(&key->u))) {
         if (mp_exptmod(tmp, &key->d, &key->n, tmp) != MP_OKAY) {
             ret = MP_EXPTMOD_E;
         }