gistfile1.txt

diff --git a/vm.c b/vm.c
index 6302153..76bfee4 100644
--- a/vm.c
+++ b/vm.c
@@ -412,6 +412,16 @@ vm_make_env_each(rb_thread_t * const th, rb_control_frame_t * const cfp,
     nenvptr = &env->env[i - 1];
     nenvptr[1] = envval;	/* frame self */
 
+    if (envptr == endptr) {
+	rb_block_t *block = GC_GUARDED_PTR_REF(*nenvptr);
+	if (block && block->proc == 0) {
+	    rb_proc_t *proc;
+	    VALUE blockval = rb_vm_make_proc(th, block, rb_cProc);
+	    GetProcPtr(blockval, proc);
+	    *nenvptr = VM_ENVVAL_BLOCK_PTR(&proc->block);
+	}
+    }
+
     /* reset ep in cfp */
     cfp->ep = nenvptr;