diff --git a/src/dump.c b/src/dump.c
index aeb23d033..6acba12c2 100644
--- a/src/dump.c
+++ b/src/dump.c
@@ -934,14 +934,19 @@ dump_pool(mrb_state *mrb, const mrb_pool_value *p, FILE *fp)
 {
   if (p->tt & IREP_TT_NFLAG) {  /* number */
     switch (p->tt) {
+#ifdef MRB_64BIT
+    case IREP_TT_INT64:
+      if (p->u.i64 < INT32_MIN || INT32_MAX < p->u.i64) {
+        fprintf(fp, "{IREP_TT_INT64, {.i64=%" PRId64 "}},\n", p->u.i64);
+      }
+      else {
+        fprintf(fp, "{IREP_TT_INT32, {.i64=%" PRId64 "}},\n", p->u.i64);
+      }
+      break;
+#endif
     case IREP_TT_INT32:
       fprintf(fp, "{IREP_TT_INT32, {.i32=%" PRId32 "}},\n", p->u.i32);
       break;
-#ifdef MRB_64BIT
-    case IREP_TT_INT64:
-      fprintf(fp, "{IREP_TT_INT64, {.i64=%" PRId64 "}},\n", p->u.i64);
-      break;
-#endif
     case IREP_TT_FLOAT:
       if (p->u.f == 0) {
         fprintf(fp, "{IREP_TT_FLOAT, {.f=%#.1f}},\n", p->u.f);
diff --git a/src/vm.c b/src/vm.c
index c97c9678c..e184e7cc6 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1018,10 +1018,16 @@ RETRY_TRY_BLOCK:
         regs[a] = mrb_fixnum_value((mrb_int)pool[b].u.i32);
         break;
       case IREP_TT_INT64:
-#if defined(MRB_INT64) && defined(MRB_64BIT)
+#if defined(MRB_INT64)
         regs[a] = mrb_fixnum_value((mrb_int)pool[b].u.i64);
         break;
 #else
+#if defined(MRB_64BIT)
+        if (INT32_MIN <= pool[b].u.i64 && pool[b].u.i64 <= INT32_MAX) {
+          regs[a] = mrb_fixnum_value((mrb_int)pool[b].u.i64);
+          break;
+        }
+#endif
         {
           mrb_value exc = mrb_exc_new_str_lit(mrb, E_RUNTIME_ERROR, "integer overflow");
           mrb_exc_set(mrb, exc);