diff --git a/src/doc/unstable-book/src/compiler-flags/check-cfg.md b/src/doc/unstable-book/src/compiler-flags/check-cfg.md
index 7a3ef5e9e2be..0e15c79076fa 100644
--- a/src/doc/unstable-book/src/compiler-flags/check-cfg.md
+++ b/src/doc/unstable-book/src/compiler-flags/check-cfg.md
@@ -139,7 +139,7 @@ fn do_mumble_frotz() {}
 
 ```bash
 # This turns on checking for feature values, but not for condition names.
-rustc --check-cfg 'configure(feature, values("zapping", "lasers"))' \
+rustc --check-cfg 'cfg(feature, values("zapping", "lasers"))' \
       --check-cfg 'cfg(any())' \
       --cfg 'feature="zapping"' -Z unstable-options
 ```