diff --git a/clippy_lints/src/casts/mod.rs b/clippy_lints/src/casts/mod.rs
index 55c1f085657..ee6be230617 100644
--- a/clippy_lints/src/casts/mod.rs
+++ b/clippy_lints/src/casts/mod.rs
@@ -487,6 +487,7 @@
     /// let y: u32 = x.abs() as u32;
     /// ```
     /// Use instead:
+    /// ```rust
     /// let x: i32 = -42;
     /// let y: u32 = x.unsigned_abs();
     /// ```