1 files changed, 3 insertions, 4 deletions
diff --git a/src/variable.c b/src/variable.c
index 0755f7d92..8c16b2d4f 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -4,7 +4,6 @@
 ** See Copyright Notice in mruby.h
 */
 
-#include <math.h>
 #include <mruby.h>
 #include <mruby/array.h>
 #include <mruby/class.h>
@@ -1132,9 +1131,9 @@ mrb_class_find_path(mrb_state *mrb, struct RClass *c)
 mrb_int
 mrb_obj_iv_tbl_memsize(mrb_state* mrb, mrb_value obj)
 {
-  return sizeof(iv_tbl) +
-    (sizeof(segment) * ceil(iv_size(mrb, mrb_obj_ptr(obj)->iv)/
-                            MRB_IV_SEGMENT_SIZE));
+  size_t ivsize = iv_size(mrb, mrb_obj_ptr(obj)->iv);
+  size_t ivsegs = (ivsize + MRB_IV_SEGMENT_SIZE - 1) / MRB_IV_SEGMENT_SIZE;
+  return sizeof(iv_tbl) + (sizeof(segment) * ivsegs);
 }
 
 #define identchar(c) (ISALNUM(c) || (c) == '_' || !ISASCII(c))