diff --git a/py/binary.h b/py/binary.h
index 2a63ba9..dc9d3f6 100644
--- a/py/binary.h
+++ b/py/binary.h
@@ -34,5 +34,5 @@
 void mp_binary_set_val_array_from_int(char typecode, void *p, mp_uint_t index, mp_int_t val);
 mp_obj_t mp_binary_get_val(char struct_type, char val_type, byte **ptr);
 void mp_binary_set_val(char struct_type, char val_type, mp_obj_t val_in, byte **ptr);
-long long mp_binary_get_int(mp_uint_t size, bool is_signed, bool big_endian, byte *p);
-void mp_binary_set_int(mp_uint_t val_sz, bool big_endian, byte *p, byte *val_ptr);
+long long mp_binary_get_int(mp_uint_t size, bool is_signed, bool big_endian, const byte *src);
+void mp_binary_set_int(mp_uint_t val_sz, bool big_endian, byte *dest, mp_uint_t val);