diff --git a/Cython/Utility/StringTools.c b/Cython/Utility/StringTools.c
index 02fd67565175b728c12b855299fb1200c0c55690_Q3l0aG9uL1V0aWxpdHkvU3RyaW5nVG9vbHMuYw==..3b5406f75a4eded7eaa9e82094f839d47d668c9f_Q3l0aG9uL1V0aWxpdHkvU3RyaW5nVG9vbHMuYw== 100644
--- a/Cython/Utility/StringTools.c
+++ b/Cython/Utility/StringTools.c
@@ -545,6 +545,7 @@
             PyObject* text, Py_ssize_t start, Py_ssize_t stop);
 
 /////////////// PyUnicode_Substring ///////////////
+//@substitute: naming
 
 static CYTHON_INLINE PyObject* __Pyx_PyUnicode_Substring(
             PyObject* text, Py_ssize_t start, Py_ssize_t stop) {