diff --git a/py/objstr.c b/py/objstr.c
index 6a0721d45f..59547e3cd6 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -35,7 +35,7 @@ mp_obj_t str_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
                 return mp_obj_new_int(lhs_str[mp_obj_get_int(rhs_in)]);
 #if MICROPY_ENABLE_SLICE
             } else if (MP_OBJ_IS_TYPE(rhs_in, &slice_type)) {
-                int start, stop, step;
+                machine_int_t start, stop, step;
                 mp_obj_slice_get(rhs_in, &start, &stop, &step);
                 assert(step == 1);
                 int len = strlen(lhs_str);
diff --git a/tests/basics/tests/slice-bstr1.py b/tests/basics/tests/slice-bstr1.py
index 8b492b35cc..0bed959141 100644
--- a/tests/basics/tests/slice-bstr1.py
+++ b/tests/basics/tests/slice-bstr1.py
@@ -1,27 +1,27 @@
-b"123"[0:1]
+print(b"123"[0:1])
 
-b"123"[0:2]
+print(b"123"[0:2])
 
-b"123"[:1]
+print(b"123"[:1])
 
-b"123"[1:]
+print(b"123"[1:])
 
 # Idiom for copying sequence
-b"123"[:]
+print(b"123"[:])
 
-b"123"[:-1]
+print(b"123"[:-1])
 
 # Weird cases
-b"123"[0:0]
-b"123"[1:0]
-b"123"[1:1]
-b"123"[-1:-1]
-b"123"[-3:]
-b"123"[-3:3]
-b"123"[0:]
-b"123"[:0]
-b"123"[:-3]
-b"123"[:-4]
+print(b"123"[0:0])
+print(b"123"[1:0])
+print(b"123"[1:1])
+print(b"123"[-1:-1])
+print(b"123"[-3:])
+print(b"123"[-3:3])
+print(b"123"[0:])
+print(b"123"[:0])
+print(b"123"[:-3])
+print(b"123"[:-4])
 # No IndexError!
-b""[1:1]
-b""[-1:-1]
+print(b""[1:1])
+print(b""[-1:-1])