Implement PEP 393.
diff --git a/Objects/stringlib/partition.h b/Objects/stringlib/partition.h
index 0170bdd..40cb512 100644
--- a/Objects/stringlib/partition.h
+++ b/Objects/stringlib/partition.h
@@ -1,14 +1,11 @@
 /* stringlib: partition implementation */
 
-#ifndef STRINGLIB_PARTITION_H
-#define STRINGLIB_PARTITION_H
-
 #ifndef STRINGLIB_FASTSEARCH_H
 #error must include "stringlib/fastsearch.h" before including this module
 #endif
 
 Py_LOCAL_INLINE(PyObject*)
-stringlib_partition(PyObject* str_obj,
+STRINGLIB(partition)(PyObject* str_obj,
                     const STRINGLIB_CHAR* str, Py_ssize_t str_len,
                     PyObject* sep_obj,
                     const STRINGLIB_CHAR* sep, Py_ssize_t sep_len)
@@ -25,7 +22,7 @@
     if (!out)
         return NULL;
 
-    pos = fastsearch(str, str_len, sep, sep_len, -1, FAST_SEARCH);
+    pos = FASTSEARCH(str, str_len, sep, sep_len, -1, FAST_SEARCH);
 
     if (pos < 0) {
 #if STRINGLIB_MUTABLE
@@ -58,7 +55,7 @@
 }
 
 Py_LOCAL_INLINE(PyObject*)
-stringlib_rpartition(PyObject* str_obj,
+STRINGLIB(rpartition)(PyObject* str_obj,
                      const STRINGLIB_CHAR* str, Py_ssize_t str_len,
                      PyObject* sep_obj,
                      const STRINGLIB_CHAR* sep, Py_ssize_t sep_len)
@@ -75,7 +72,7 @@
     if (!out)
         return NULL;
 
-    pos = fastsearch(str, str_len, sep, sep_len, -1, FAST_RSEARCH);
+    pos = FASTSEARCH(str, str_len, sep, sep_len, -1, FAST_RSEARCH);
 
     if (pos < 0) {
 #if STRINGLIB_MUTABLE
@@ -107,4 +104,3 @@
     return out;
 }
 
-#endif