1 files changed, 1 insertions, 4 deletions
diff --git a/mrbgems/mruby-fiber/src/fiber.c b/mrbgems/mruby-fiber/src/fiber.c
index b702a3811..e47849dda 100644
--- a/mrbgems/mruby-fiber/src/fiber.c
+++ b/mrbgems/mruby-fiber/src/fiber.c
@@ -72,14 +72,11 @@ fiber_init(mrb_state *mrb, mrb_value self)
   mrb_value blk;
   size_t slen;
 
-  mrb_get_args(mrb, "&", &blk);
+  mrb_get_args(mrb, "&!", &blk);
 
   if (f->cxt) {
     mrb_raise(mrb, E_RUNTIME_ERROR, "cannot initialize twice");
   }
-  if (mrb_nil_p(blk)) {
-    mrb_raise(mrb, E_ARGUMENT_ERROR, "tried to create Fiber object without a block");
-  }
   p = mrb_proc_ptr(blk);
   if (MRB_PROC_CFUNC_P(p)) {
     mrb_raise(mrb, E_FIBER_ERROR, "tried to create Fiber from C defined method");