diff --git a/Include/bytearrayobject.h b/Include/bytearrayobject.h
new file mode 100644
index 0000000..2c0b734
--- /dev/null
+++ b/Include/bytearrayobject.h
@@ -0,0 +1,53 @@
+/* Bytes object interface */
+
+#ifndef Py_BYTESOBJECT_H
+#define Py_BYTESOBJECT_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdarg.h>
+
+/* Type PyByteArrayObject represents a mutable array of bytes.
+ * The Python API is that of a sequence;
+ * the bytes are mapped to ints in [0, 256).
+ * Bytes are not characters; they may be used to encode characters.
+ * The only way to go between bytes and str/unicode is via encoding
+ * and decoding.
+ * For the convenience of C programmers, the bytes type is considered
+ * to contain a char pointer, not an unsigned char pointer.
+ */
+
+/* Object layout */
+typedef struct {
+    PyObject_VAR_HEAD
+    /* XXX(nnorwitz): should ob_exports be Py_ssize_t? */
+    int ob_exports; /* how many buffer exports */
+    Py_ssize_t ob_alloc; /* How many bytes allocated */
+    char *ob_bytes;
+} PyByteArrayObject;
+
+/* Type object */
+PyAPI_DATA(PyTypeObject) PyByteArray_Type;
+PyAPI_DATA(PyTypeObject) PyByteArrayIter_Type;
+
+/* Type check macros */
+#define PyByteArray_Check(self) PyObject_TypeCheck(self, &PyByteArray_Type)
+#define PyByteArray_CheckExact(self) (Py_TYPE(self) == &PyByteArray_Type)
+
+/* Direct API functions */
+PyAPI_FUNC(PyObject *) PyByteArray_FromObject(PyObject *);
+PyAPI_FUNC(PyObject *) PyByteArray_Concat(PyObject *, PyObject *);
+PyAPI_FUNC(PyObject *) PyByteArray_FromStringAndSize(const char *, Py_ssize_t);
+PyAPI_FUNC(Py_ssize_t) PyByteArray_Size(PyObject *);
+PyAPI_FUNC(char *) PyByteArray_AsString(PyObject *);
+PyAPI_FUNC(int) PyByteArray_Resize(PyObject *, Py_ssize_t);
+
+/* Macros, trading safety for speed */
+#define PyByteArray_AS_STRING(self) (assert(PyByteArray_Check(self)),((PyByteArrayObject *)(self))->ob_bytes)
+#define PyByteArray_GET_SIZE(self)  (assert(PyByteArray_Check(self)),Py_SIZE(self))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* !Py_BYTESOBJECT_H */