diff --git a/blog/content/second-edition/posts/05-integration-tests/index.md b/blog/content/second-edition/posts/05-integration-tests/index.md
index 78ff82cc..a42bf319 100644
--- a/blog/content/second-edition/posts/05-integration-tests/index.md
+++ b/blog/content/second-edition/posts/05-integration-tests/index.md
@@ -116,7 +116,8 @@ macro_rules! serial_print {
 macro_rules! serial_println {
     () => ($crate::serial_print!("\n"));
     ($fmt:expr) => ($crate::serial_print!(concat!($fmt, "\n")));
-    ($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(concat!($fmt, "\n"), $($arg)*));
+    ($fmt:expr, $($arg:tt)*) => ($crate::serial_print!(
+        concat!($fmt, "\n"), $($arg)*));
 }
 ```