diff --git a/dap_chain_mempool.c b/dap_chain_mempool.c
index 038eb33967638ec957150433deb6bcbac6fb8c52..2f397ba917b79e6c7e96faf31a4bceaca0ec96bd 100755
--- a/dap_chain_mempool.c
+++ b/dap_chain_mempool.c
@@ -290,11 +290,11 @@ void dap_datum_mempool_free(dap_datum_mempool_t *datum)
  */
 static char* calc_datum_hash(const char *datum_str, size_t datum_size)
 {
-    dap_chain_hash_t a_hash;
+    dap_chain_hash_fast_t a_hash;
     dap_hash((char*) datum_str, datum_size, a_hash.raw, sizeof(a_hash.raw), DAP_HASH_TYPE_SLOW_0);
     size_t a_str_max = (sizeof(a_hash.raw) + 1) * 2 + 2; /* heading 0x */
     char *a_str = DAP_NEW_Z_SIZE(char, a_str_max);
-    size_t hash_len = dap_chain_hash_to_str(&a_hash, a_str, a_str_max);
+    size_t hash_len = dap_chain_hash_fast_to_str(&a_hash, a_str, a_str_max);
     if(!hash_len) {
         DAP_DELETE(a_str);
         return NULL;