1 files changed, 2 insertions, 2 deletions
diff --git a/Modules/_io/bytesio.c b/Modules/_io/bytesio.c
index b5d308a8bc..f4261b3713 100644
--- a/Modules/_io/bytesio.c
+++ b/Modules/_io/bytesio.c
@@ -393,7 +393,7 @@ _io_BytesIO_tell_impl(bytesio *self)
 static PyObject *
 read_bytes(bytesio *self, Py_ssize_t size)
 {
-    char *output;
+    const char *output;
 
     assert(self->buf != NULL);
     assert(size <= self->string_size);
@@ -502,7 +502,7 @@ _io_BytesIO_readlines_impl(bytesio *self, PyObject *arg)
 {
     Py_ssize_t maxsize, size, n;
     PyObject *result, *line;
-    char *output;
+    const char *output;
 
     CHECK_CLOSED(self);