diff --git a/src/header/string/cbindgen.toml b/src/header/string/cbindgen.toml
index 9cee2c5da5..d5ae1e23b7 100644
--- a/src/header/string/cbindgen.toml
+++ b/src/header/string/cbindgen.toml
@@ -1,4 +1,4 @@
-sys_includes = ["stddef.h", "stdint.h", "strings.h"]
+sys_includes = ["stddef.h", "stdint.h", "strings.h", "locale.h"]
 include_guard = "_RELIBC_STRING_H"
 language = "C"
 style = "Tag"