diff --git a/src/doc/unstable-book/src/compiler-flags/sanitizer.md b/src/doc/unstable-book/src/compiler-flags/sanitizer.md
index 262cef3454ad3..3282ff720c478 100644
--- a/src/doc/unstable-book/src/compiler-flags/sanitizer.md
+++ b/src/doc/unstable-book/src/compiler-flags/sanitizer.md
@@ -213,7 +213,7 @@ See the [Clang ControlFlowIntegrity documentation][clang-cfi] for more details.
 
 ## Example
 
-```text
+```rust
 #![feature(naked_functions)]
 
 use std::arch::asm;