diff --git a/src/dump.c b/src/dump.c
index 3841e12ac..97acf1024 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -131,7 +131,6 @@ get_pool_block_size(mrb_state *mrb, const mrb_irep *irep)
       {
         mrb_int len = irep->pool[pool_no].u.str[0];
         mrb_assert_int_fit(mrb_int, len, size_t, SIZE_MAX);
-        size += sizeof(uint8_t);
         size += (size_t)len+2;
       }
       break;
@@ -199,7 +198,6 @@ write_pool_block(mrb_state *mrb, const mrb_irep *irep, uint8_t *buf)
       len = irep->pool[pool_no].u.str[0];
       memcpy(cur, irep->pool[pool_no].u.str, (size_t)len+2);
       cur += len+2;
-      *cur++ = '\0';
       break;
 
     case IREP_TT_FLOAT:
diff --git a/src/load.c b/src/load.c
index ee8d1f223..1916c6c9d 100644
--- a/src/load.c
+++ b/src/load.c
@@ -163,16 +163,16 @@ read_irep_record_1(mrb_state *mrb, const uint8_t *bin, const uint8_t *end, size_
 #endif
 
       case IREP_TT_BIGINT:
-        pool_data_len = bin_to_uint8(src); /* pool data length */
+        pool_data_len = bin_to_uint8(src) + 2; /* pool data length */
         if (src + pool_data_len > end) return FALSE;
-        {
+        else {
           char *p;
           pool[i].tt = IREP_TT_BIGINT;
-          p = (char*)mrb_malloc(mrb, pool_data_len+2);
-          memcpy(p, src, pool_data_len+2);
+          p = (char*)mrb_malloc(mrb, pool_data_len);
+          memcpy(p, src, pool_data_len);
           pool[i].u.str = (const char*)p;
         }
-        src += pool_data_len + 2;
+        src += pool_data_len;
         break;
 
       case IREP_TT_FLOAT: