diff --git a/src/bcrypt_pbkdf.c b/src/bcrypt_pbkdf.c
index f9a97580..f782bcac 100644
--- a/src/bcrypt_pbkdf.c
+++ b/src/bcrypt_pbkdf.c
@@ -81,7 +81,7 @@ bcrypt_hash(uint8_t *sha2pass, uint8_t *sha2salt, uint8_t *out)
         cdata[i] = Blowfish_stream2word(ciphertext, sizeof(ciphertext),
                                         &j);
     for(i = 0; i < 64; i++)
-        blf_enc(&state, cdata, sizeof(cdata) / sizeof(uint64_t));
+        blf_enc(&state, cdata, BCRYPT_BLOCKS / 2);
 
     /* copy out */
     for(i = 0; i < BCRYPT_BLOCKS; i++) {