diff --git a/Objects/stringlib/asciilib.h b/Objects/stringlib/asciilib.h
index bfd5d75a3c8..f6f733339c1 100644
--- a/Objects/stringlib/asciilib.h
+++ b/Objects/stringlib/asciilib.h
@@ -17,7 +17,6 @@
 #define STRINGLIB_TODECIMAL      Py_UNICODE_TODECIMAL
 #define STRINGLIB_TOUPPER        Py_UNICODE_TOUPPER
 #define STRINGLIB_TOLOWER        Py_UNICODE_TOLOWER
-#define STRINGLIB_FILL           Py_UNICODE_FILL
 #define STRINGLIB_STR            PyUnicode_1BYTE_DATA
 #define STRINGLIB_LEN            PyUnicode_GET_LENGTH
 #define STRINGLIB_NEW            unicode_fromascii
diff --git a/Objects/stringlib/stringdefs.h b/Objects/stringlib/stringdefs.h
index 41449fce4e7..7d300595468 100644
--- a/Objects/stringlib/stringdefs.h
+++ b/Objects/stringlib/stringdefs.h
@@ -20,7 +20,6 @@
 #define STRINGLIB_TODECIMAL(x)   (STRINGLIB_ISDECIMAL(x) ? (x - '0') : -1)
 #define STRINGLIB_TOUPPER        Py_TOUPPER
 #define STRINGLIB_TOLOWER        Py_TOLOWER
-#define STRINGLIB_FILL           memset
 #define STRINGLIB_STR            PyBytes_AS_STRING
 #define STRINGLIB_LEN            PyBytes_GET_SIZE
 #define STRINGLIB_NEW            PyBytes_FromStringAndSize
diff --git a/Objects/stringlib/ucs1lib.h b/Objects/stringlib/ucs1lib.h
index 0b82a84e97d..2c78bd26e9c 100644
--- a/Objects/stringlib/ucs1lib.h
+++ b/Objects/stringlib/ucs1lib.h
@@ -17,7 +17,6 @@
 #define STRINGLIB_TODECIMAL      Py_UNICODE_TODECIMAL
 #define STRINGLIB_TOUPPER        Py_UNICODE_TOUPPER
 #define STRINGLIB_TOLOWER        Py_UNICODE_TOLOWER
-#define STRINGLIB_FILL           Py_UNICODE_FILL
 #define STRINGLIB_STR            PyUnicode_1BYTE_DATA
 #define STRINGLIB_LEN            PyUnicode_GET_LENGTH
 #define STRINGLIB_NEW            _PyUnicode_FromUCS1
diff --git a/Objects/stringlib/ucs2lib.h b/Objects/stringlib/ucs2lib.h
index e2e8c1be0fe..cb8bc64de8e 100644
--- a/Objects/stringlib/ucs2lib.h
+++ b/Objects/stringlib/ucs2lib.h
@@ -17,7 +17,6 @@
 #define STRINGLIB_TODECIMAL      Py_UNICODE_TODECIMAL
 #define STRINGLIB_TOUPPER        Py_UNICODE_TOUPPER
 #define STRINGLIB_TOLOWER        Py_UNICODE_TOLOWER
-#define STRINGLIB_FILL           Py_UNICODE_FILL
 #define STRINGLIB_STR            PyUnicode_2BYTE_DATA
 #define STRINGLIB_LEN            PyUnicode_GET_LENGTH
 #define STRINGLIB_NEW            _PyUnicode_FromUCS2
diff --git a/Objects/stringlib/ucs4lib.h b/Objects/stringlib/ucs4lib.h
index 0ca86604767..7cd7b339f54 100644
--- a/Objects/stringlib/ucs4lib.h
+++ b/Objects/stringlib/ucs4lib.h
@@ -17,7 +17,6 @@
 #define STRINGLIB_TODECIMAL      Py_UNICODE_TODECIMAL
 #define STRINGLIB_TOUPPER        Py_UNICODE_TOUPPER
 #define STRINGLIB_TOLOWER        Py_UNICODE_TOLOWER
-#define STRINGLIB_FILL           Py_UNICODE_FILL
 #define STRINGLIB_STR            PyUnicode_4BYTE_DATA
 #define STRINGLIB_LEN            PyUnicode_GET_LENGTH
 #define STRINGLIB_NEW            _PyUnicode_FromUCS4
diff --git a/Objects/stringlib/unicodedefs.h b/Objects/stringlib/unicodedefs.h
index 5c0761a74c4..a38162ba16d 100644
--- a/Objects/stringlib/unicodedefs.h
+++ b/Objects/stringlib/unicodedefs.h
@@ -20,7 +20,6 @@
 #define STRINGLIB_TODECIMAL      Py_UNICODE_TODECIMAL
 #define STRINGLIB_TOUPPER        Py_UNICODE_TOUPPER
 #define STRINGLIB_TOLOWER        Py_UNICODE_TOLOWER
-#define STRINGLIB_FILL           Py_UNICODE_FILL
 #define STRINGLIB_STR            PyUnicode_AS_UNICODE
 #define STRINGLIB_LEN            PyUnicode_GET_SIZE
 #define STRINGLIB_NEW            PyUnicode_FromUnicode