diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000..5d56faf
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"
diff --git a/src/main.rs b/src/main.rs
index 68e08cf..50a6488 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,10 @@
+use core::fmt::NumBuffer;
 use std::io::{self, BufWriter, Write};
 
 fn main() {
+    let mut buf = NumBuffer::new();
     let mut stdout = BufWriter::new(io::stdout());
-    for i in 0u64.. {
-        writeln!(stdout, "{i}").unwrap();
+    for i in 0..u64::MAX {
+        writeln!(stdout, "{}", i.format_into(&mut buf)).unwrap();
     }
 }