diff --git a/mrbgems/mruby-kernel-ext/src/kernel.c b/mrbgems/mruby-kernel-ext/src/kernel.c
index b6c598d2f..a0c274dcf 100644
--- a/mrbgems/mruby-kernel-ext/src/kernel.c
+++ b/mrbgems/mruby-kernel-ext/src/kernel.c
@@ -191,7 +191,7 @@ mrb_f_float(mrb_state *mrb, mrb_value self)
   if (mrb_string_p(arg)) {
     return mrb_float_value(mrb, mrb_str_to_dbl(mrb, arg, TRUE));
   }
-  return mrb_to_float(mrb, arg);
+  return mrb_ensure_float_type(mrb, arg);
 }
 #endif
 
diff --git a/mrbgems/mruby-pack/src/pack.c b/mrbgems/mruby-pack/src/pack.c
index 47ad3d85a..cd9202404 100644
--- a/mrbgems/mruby-pack/src/pack.c
+++ b/mrbgems/mruby-pack/src/pack.c
@@ -1395,8 +1395,7 @@ mrb_pack_pack(mrb_state *mrb, mrb_value ary)
 #ifndef MRB_NO_FLOAT
       else if (type == PACK_TYPE_FLOAT) {
         if (!mrb_float_p(o)) {
-          mrb_float f = mrb_as_float(mrb, o);
-          o = mrb_float_value(mrb, f);
+          o = mrb_ensure_float_type(mrb, o);
         }
       }
 #endif
diff --git a/src/numeric.c b/src/numeric.c
index be49c9e70..08599901b 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -259,7 +259,7 @@ coerce_step_counter(mrb_state *mrb, mrb_value self)
 #ifndef MRB_NO_FLOAT
   mrb->c->ci->mid = 0;
   if (mrb_float_p(num) || mrb_float_p(step)) {
-    return mrb_to_float(mrb, self);
+    return mrb_ensure_float_type(mrb, self);
   }
 #endif