diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 5688783ab1..2f59c3a625 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -706,14 +706,14 @@ qcrypto_block_luks_store_key(QCryptoBlock *block,
 
     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
     slot = &luks->header.key_slots[slot_idx];
+    splitkeylen = luks->header.master_key_len * slot->stripes;
+
     if (qcrypto_random_bytes(slot->salt,
                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
                              errp) < 0) {
         goto cleanup;
     }
 
-    splitkeylen = luks->header.master_key_len * slot->stripes;
-
     /*
      * Determine how many iterations are required to
      * hash the user password while consuming 1 second of compute