diff --git a/std/src/sys/path/unsupported_backslash.rs b/std/src/sys/path/unsupported_backslash.rs
index 7045c9be25b08..855f443678c6c 100644
--- a/std/src/sys/path/unsupported_backslash.rs
+++ b/std/src/sys/path/unsupported_backslash.rs
@@ -1,3 +1,4 @@
+#![forbid(unsafe_op_in_unsafe_fn)]
 use crate::ffi::OsStr;
 use crate::io;
 use crate::path::{Path, PathBuf, Prefix};