@@ -2529,6 +2529,10 @@ PyBytesWriter_WriteBytes(PyBytesWriter *writer,
     return 0;
 }
 
+static inline int
+PyBytesWriter_Format(PyBytesWriter *writer, const char *format, ...)
+                     Py_GCC_ATTRIBUTE((format(printf, 2, 0)));
+
 static inline int
 PyBytesWriter_Format(PyBytesWriter *writer, const char *format, ...)
 {
 
@@ -34,7 +34,11 @@
         '-Wconversion',
         # /usr/lib64/pypy3.7/include/pyport.h:68:20: error: redefinition of typedef
         # 'Py_hash_t' is a C11 feature
-        "-Wno-typedef-redefinition",
+        '-Wno-typedef-redefinition',
+        # Formatting checks
+        '-Wformat',
+        '-Wformat-nonliteral',
+        '-Wformat-security',
     ))
     CFLAGS = COMMON_FLAGS + [
         # Use C99 for pythoncapi_compat.c which initializes PyModuleDef with a
Original file line number	Diff line number	Diff line change
@@ -2529,6 +2529,10 @@ PyBytesWriter_WriteBytes(PyBytesWriter *writer,
2529	2529	return 0;
2530	2530	}
2531	2531
	2532	+ static inline int
	2533	+ PyBytesWriter_Format(PyBytesWriter writer, const char format, ...)
	2534	+ Py_GCC_ATTRIBUTE((format(printf, 2, 0)));
	2535	+
2532	2536	static inline int
2533	2537	PyBytesWriter_Format(PyBytesWriter writer, const char format, ...)
2534	2538	{