diff --git a/src/ch18-01-what-is-oo.md b/src/ch18-01-what-is-oo.md
index 8e81826b9..3d977dadc 100644
--- a/src/ch18-01-what-is-oo.md
+++ b/src/ch18-01-what-is-oo.md
@@ -44,7 +44,7 @@ on demand whenever anyone needs it. In other words, `AveragedCollection` will
cache the calculated average for us. Listing 18-1 has the definition of the
`AveragedCollection` struct:
-
+
```rust,noplayground
{{#rustdoc_include ../listings/ch18-oop/listing-18-01/src/lib.rs}}
@@ -58,9 +58,7 @@ ensure that whenever a value is added or removed from the list, the average is
also updated. We do this by implementing `add`, `remove`, and `average` methods
on the struct, as shown in Listing 18-2:
-
-
-Filename: src/lib.rs
+
```rust,noplayground
{{#rustdoc_include ../listings/ch18-oop/listing-18-02/src/lib.rs:here}}