diff --git a/cc3200/mods/modnetwork.c b/cc3200/mods/modnetwork.c
index 8f9ee2c6c0..3031c5e790 100644
--- a/cc3200/mods/modnetwork.c
+++ b/cc3200/mods/modnetwork.c
@@ -54,7 +54,7 @@ STATIC mp_obj_t network_server_running(mp_uint_t n_args, const mp_obj_t *args) {
         return mp_const_none;
     } else {
         // get
-        return MP_BOOL(servers_are_enabled());
+        return mp_obj_new_bool(servers_are_enabled());
     }
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(network_server_running_obj, 0, 1, network_server_running);
diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 0767ab23b4..1f33ab75ec 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -534,7 +534,7 @@ STATIC mp_obj_t mp_builtin_hasattr(mp_obj_t object_in, mp_obj_t attr_in) {
     // in nlr_push and handle exception.
     mp_load_method_maybe(object_in, MP_OBJ_QSTR_VALUE(attr_in), dest);
 
-    return MP_BOOL(dest[0] != MP_OBJ_NULL);
+    return mp_obj_new_bool(dest[0] != MP_OBJ_NULL);
 }
 MP_DEFINE_CONST_FUN_OBJ_2(mp_builtin_hasattr_obj, mp_builtin_hasattr);
 
diff --git a/py/modgc.c b/py/modgc.c
index 47980decaf..007ea40a10 100644
--- a/py/modgc.c
+++ b/py/modgc.c
@@ -63,7 +63,7 @@ STATIC mp_obj_t gc_enable(void) {
 MP_DEFINE_CONST_FUN_OBJ_0(gc_enable_obj, gc_enable);
 
 STATIC mp_obj_t gc_isenabled(void) {
-    return MP_BOOL(MP_STATE_MEM(gc_auto_collect_enabled));
+    return mp_obj_new_bool(MP_STATE_MEM(gc_auto_collect_enabled));
 }
 MP_DEFINE_CONST_FUN_OBJ_0(gc_isenabled_obj, gc_isenabled);
 
diff --git a/py/modmath.c b/py/modmath.c
index 296d16be6f..e1f6b9ea08 100644
--- a/py/modmath.c
+++ b/py/modmath.c
@@ -45,7 +45,7 @@
     STATIC MP_DEFINE_CONST_FUN_OBJ_2(mp_math_## py_name ## _obj, mp_math_ ## py_name);
 
 #define MATH_FUN_1_TO_BOOL(py_name, c_name) \
-    STATIC mp_obj_t mp_math_ ## py_name(mp_obj_t x_obj) { return MP_BOOL(c_name(mp_obj_get_float(x_obj))); } \
+    STATIC mp_obj_t mp_math_ ## py_name(mp_obj_t x_obj) { return mp_obj_new_bool(c_name(mp_obj_get_float(x_obj))); } \
     STATIC MP_DEFINE_CONST_FUN_OBJ_1(mp_math_## py_name ## _obj, mp_math_ ## py_name);
 
 #define MATH_FUN_1_TO_INT(py_name, c_name) \
diff --git a/py/nativeglue.c b/py/nativeglue.c
index 87213710cf..9c939c7ea8 100644
--- a/py/nativeglue.c
+++ b/py/nativeglue.c
@@ -67,7 +67,7 @@ mp_obj_t mp_convert_native_to_obj(mp_uint_t val, mp_uint_t type) {
     DEBUG_printf("mp_convert_native_to_obj(" UINT_FMT ", " UINT_FMT ")\n", val, type);
     switch (type & 3) {
         case MP_NATIVE_TYPE_OBJ: return (mp_obj_t)val;
-        case MP_NATIVE_TYPE_BOOL: return MP_BOOL(val);
+        case MP_NATIVE_TYPE_BOOL: return mp_obj_new_bool(val);
         case MP_NATIVE_TYPE_INT: return mp_obj_new_int(val);
         case MP_NATIVE_TYPE_UINT: return mp_obj_new_int_from_uint(val);
         default: assert(0); return mp_const_none;
diff --git a/py/obj.h b/py/obj.h
index 08fc334c97..745186802c 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -459,7 +459,7 @@ extern const struct _mp_obj_exception_t mp_const_GeneratorExit_obj;
 
 mp_obj_t mp_obj_new_type(qstr name, mp_obj_t bases_tuple, mp_obj_t locals_dict);
 mp_obj_t mp_obj_new_none(void);
-mp_obj_t mp_obj_new_bool(bool value);
+static inline mp_obj_t mp_obj_new_bool(mp_int_t x) { return x ? mp_const_true : mp_const_false; }
 mp_obj_t mp_obj_new_cell(mp_obj_t obj);
 mp_obj_t mp_obj_new_int(mp_int_t value);
 mp_obj_t mp_obj_new_int_from_uint(mp_uint_t value);
@@ -528,10 +528,6 @@ mp_obj_t mp_obj_len_maybe(mp_obj_t o_in); // may return MP_OBJ_NULL
 mp_obj_t mp_obj_subscr(mp_obj_t base, mp_obj_t index, mp_obj_t val);
 mp_obj_t mp_generic_unary_op(mp_uint_t op, mp_obj_t o_in);
 
-// bool
-// TODO make lower case when it has proven itself
-static inline mp_obj_t MP_BOOL(mp_int_t x) { return x ? mp_const_true : mp_const_false; }
-
 // cell
 mp_obj_t mp_obj_cell_get(mp_obj_t self_in);
 void mp_obj_cell_set(mp_obj_t self_in, mp_obj_t obj);
diff --git a/py/objarray.c b/py/objarray.c
index 3f432f00b9..67bb7931e9 100644
--- a/py/objarray.c
+++ b/py/objarray.c
@@ -246,7 +246,7 @@ STATIC mp_obj_t memoryview_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_
 STATIC mp_obj_t array_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_array_t *o = o_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(o->len != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(o->len != 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(o->len);
         default: return MP_OBJ_NULL; // op not supported
     }
@@ -290,7 +290,7 @@ STATIC mp_obj_t array_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in)
             if (!mp_get_buffer(rhs_in, &rhs_bufinfo, MP_BUFFER_READ)) {
                 return mp_const_false;
             }
-            return MP_BOOL(mp_seq_cmp_bytes(op, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len));
+            return mp_obj_new_bool(mp_seq_cmp_bytes(op, lhs_bufinfo.buf, lhs_bufinfo.len, rhs_bufinfo.buf, rhs_bufinfo.len));
         }
 
         default:
diff --git a/py/objcomplex.c b/py/objcomplex.c
index b790b05638..231ccf7689 100644
--- a/py/objcomplex.c
+++ b/py/objcomplex.c
@@ -116,7 +116,7 @@ STATIC mp_obj_t complex_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n
 STATIC mp_obj_t complex_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_complex_t *o = o_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(o->real != 0 || o->imag != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(o->real != 0 || o->imag != 0);
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_complex(-o->real, -o->imag);
         default: return MP_OBJ_NULL; // op not supported
@@ -240,7 +240,7 @@ mp_obj_t mp_obj_complex_binary_op(mp_uint_t op, mp_float_t lhs_real, mp_float_t
             break;
         }
 
-        case MP_BINARY_OP_EQUAL: return MP_BOOL(lhs_real == rhs_real && lhs_imag == rhs_imag);
+        case MP_BINARY_OP_EQUAL: return mp_obj_new_bool(lhs_real == rhs_real && lhs_imag == rhs_imag);
 
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/objdict.c b/py/objdict.c
index c4725705d2..725c708c25 100644
--- a/py/objdict.c
+++ b/py/objdict.c
@@ -103,7 +103,7 @@ STATIC mp_obj_t dict_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw
 STATIC mp_obj_t dict_unary_op(mp_uint_t op, mp_obj_t self_in) {
     mp_obj_dict_t *self = MP_OBJ_CAST(self_in);
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(self->map.used != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(self->map.used != 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(self->map.used);
         default: return MP_OBJ_NULL; // op not supported
     }
@@ -114,7 +114,7 @@ STATIC mp_obj_t dict_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
     switch (op) {
         case MP_BINARY_OP_IN: {
             mp_map_elem_t *elem = mp_map_lookup(&o->map, rhs_in, MP_MAP_LOOKUP);
-            return MP_BOOL(elem != NULL);
+            return mp_obj_new_bool(elem != NULL);
         }
         case MP_BINARY_OP_EQUAL: {
             #if MICROPY_PY_COLLECTIONS_ORDEREDDICT
diff --git a/py/objfloat.c b/py/objfloat.c
index 0af41990ff..b8ab882b5c 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -85,7 +85,7 @@ STATIC mp_obj_t float_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_k
 STATIC mp_obj_t float_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_float_t *o = o_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(o->value != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(o->value != 0);
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: return mp_obj_new_float(-o->value);
         default: return MP_OBJ_NULL; // op not supported
@@ -216,11 +216,11 @@ mp_obj_t mp_obj_float_binary_op(mp_uint_t op, mp_float_t lhs_val, mp_obj_t rhs_i
             };
             return mp_obj_new_tuple(2, tuple);
         }
-        case MP_BINARY_OP_LESS: return MP_BOOL(lhs_val < rhs_val);
-        case MP_BINARY_OP_MORE: return MP_BOOL(lhs_val > rhs_val);
-        case MP_BINARY_OP_EQUAL: return MP_BOOL(lhs_val == rhs_val);
-        case MP_BINARY_OP_LESS_EQUAL: return MP_BOOL(lhs_val <= rhs_val);
-        case MP_BINARY_OP_MORE_EQUAL: return MP_BOOL(lhs_val >= rhs_val);
+        case MP_BINARY_OP_LESS: return mp_obj_new_bool(lhs_val < rhs_val);
+        case MP_BINARY_OP_MORE: return mp_obj_new_bool(lhs_val > rhs_val);
+        case MP_BINARY_OP_EQUAL: return mp_obj_new_bool(lhs_val == rhs_val);
+        case MP_BINARY_OP_LESS_EQUAL: return mp_obj_new_bool(lhs_val <= rhs_val);
+        case MP_BINARY_OP_MORE_EQUAL: return mp_obj_new_bool(lhs_val >= rhs_val);
 
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/objint_longlong.c b/py/objint_longlong.c
index 075fabe49d..bceee095af 100644
--- a/py/objint_longlong.c
+++ b/py/objint_longlong.c
@@ -106,7 +106,7 @@ mp_obj_t mp_obj_int_abs(mp_obj_t self_in) {
 mp_obj_t mp_obj_int_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_int_t *o = o_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(o->val != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(o->val != 0);
 
         // truncate value to fit in mp_int_t, which gives the same hash as
         // small int if the value fits without truncation
@@ -191,15 +191,15 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
         }
 
         case MP_BINARY_OP_LESS:
-            return MP_BOOL(lhs_val < rhs_val);
+            return mp_obj_new_bool(lhs_val < rhs_val);
         case MP_BINARY_OP_MORE:
-            return MP_BOOL(lhs_val > rhs_val);
+            return mp_obj_new_bool(lhs_val > rhs_val);
         case MP_BINARY_OP_LESS_EQUAL:
-            return MP_BOOL(lhs_val <= rhs_val);
+            return mp_obj_new_bool(lhs_val <= rhs_val);
         case MP_BINARY_OP_MORE_EQUAL:
-            return MP_BOOL(lhs_val >= rhs_val);
+            return mp_obj_new_bool(lhs_val >= rhs_val);
         case MP_BINARY_OP_EQUAL:
-            return MP_BOOL(lhs_val == rhs_val);
+            return mp_obj_new_bool(lhs_val == rhs_val);
 
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/objint_mpz.c b/py/objint_mpz.c
index 73469f30d3..2255fd6525 100644
--- a/py/objint_mpz.c
+++ b/py/objint_mpz.c
@@ -145,7 +145,7 @@ mp_obj_t mp_obj_int_abs(mp_obj_t self_in) {
 mp_obj_t mp_obj_int_unary_op(mp_uint_t op, mp_obj_t o_in) {
     mp_obj_int_t *o = o_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(!mpz_is_zero(&o->mpz));
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(!mpz_is_zero(&o->mpz));
         case MP_UNARY_OP_HASH: return MP_OBJ_NEW_SMALL_INT(mpz_hash(&o->mpz));
         case MP_UNARY_OP_POSITIVE: return o_in;
         case MP_UNARY_OP_NEGATIVE: { mp_obj_int_t *o2 = mp_obj_int_new_mpz(); mpz_neg_inpl(&o2->mpz, &o->mpz); return o2; }
@@ -308,15 +308,15 @@ mp_obj_t mp_obj_int_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
         int cmp = mpz_cmp(zlhs, zrhs);
         switch (op) {
             case MP_BINARY_OP_LESS:
-                return MP_BOOL(cmp < 0);
+                return mp_obj_new_bool(cmp < 0);
             case MP_BINARY_OP_MORE:
-                return MP_BOOL(cmp > 0);
+                return mp_obj_new_bool(cmp > 0);
             case MP_BINARY_OP_LESS_EQUAL:
-                return MP_BOOL(cmp <= 0);
+                return mp_obj_new_bool(cmp <= 0);
             case MP_BINARY_OP_MORE_EQUAL:
-                return MP_BOOL(cmp >= 0);
+                return mp_obj_new_bool(cmp >= 0);
             case MP_BINARY_OP_EQUAL:
-                return MP_BOOL(cmp == 0);
+                return mp_obj_new_bool(cmp == 0);
 
             default:
                 return MP_OBJ_NULL; // op not supported
diff --git a/py/objlist.c b/py/objlist.c
index 21220441b5..5a90719a5e 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -102,7 +102,7 @@ STATIC bool list_cmp_helper(mp_uint_t op, mp_obj_t self_in, mp_obj_t another_in)
 STATIC mp_obj_t list_unary_op(mp_uint_t op, mp_obj_t self_in) {
     mp_obj_list_t *self = MP_OBJ_CAST(self_in);
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(self->len != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(self->len != 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(self->len);
         default: return MP_OBJ_NULL; // op not supported
     }
@@ -141,7 +141,7 @@ STATIC mp_obj_t list_binary_op(mp_uint_t op, mp_obj_t lhs, mp_obj_t rhs) {
         case MP_BINARY_OP_LESS_EQUAL:
         case MP_BINARY_OP_MORE:
         case MP_BINARY_OP_MORE_EQUAL:
-            return MP_BOOL(list_cmp_helper(op, lhs, rhs));
+            return mp_obj_new_bool(list_cmp_helper(op, lhs, rhs));
 
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/objrange.c b/py/objrange.c
index 9d0ca37a74..f703f2fb0f 100644
--- a/py/objrange.c
+++ b/py/objrange.c
@@ -131,7 +131,7 @@ STATIC mp_obj_t range_unary_op(mp_uint_t op, mp_obj_t self_in) {
     mp_obj_range_t *self = self_in;
     mp_int_t len = range_len(self);
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(len > 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(len > 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(len);
         default: return MP_OBJ_NULL; // op not supported
     }
diff --git a/py/objset.c b/py/objset.c
index 9b70ce6289..55aedde3eb 100644
--- a/py/objset.c
+++ b/py/objset.c
@@ -366,7 +366,7 @@ STATIC mp_obj_t set_issubset_internal(mp_obj_t self_in, mp_obj_t other_in, bool
     if (cleanup_other) {
         set_clear(other);
     }
-    return MP_BOOL(out);
+    return mp_obj_new_bool(out);
 }
 STATIC mp_obj_t set_issubset(mp_obj_t self_in, mp_obj_t other_in) {
     return set_issubset_internal(self_in, other_in, false);
@@ -471,7 +471,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(set_union_obj, set_union);
 STATIC mp_obj_t set_unary_op(mp_uint_t op, mp_obj_t self_in) {
     mp_obj_set_t *self = self_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(self->set.used != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(self->set.used != 0);
         case MP_UNARY_OP_LEN: return MP_OBJ_NEW_SMALL_INT(self->set.used);
 #if MICROPY_PY_BUILTINS_FROZENSET
         case MP_UNARY_OP_HASH:
@@ -525,7 +525,7 @@ STATIC mp_obj_t set_binary_op(mp_uint_t op, mp_obj_t lhs, mp_obj_t rhs) {
         case MP_BINARY_OP_IN: {
             mp_obj_set_t *o = lhs;
             mp_obj_t elem = mp_set_lookup(&o->set, rhs, MP_MAP_LOOKUP);
-            return MP_BOOL(elem != NULL);
+            return mp_obj_new_bool(elem != NULL);
         }
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/objstr.c b/py/objstr.c
index 9982322490..f94744af7f 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -360,7 +360,7 @@ mp_obj_t mp_obj_str_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
 
         case MP_BINARY_OP_IN:
             /* NOTE `a in b` is `b.__contains__(a)` */
-            return MP_BOOL(find_subbytes(lhs_data, lhs_len, rhs_data, rhs_len, 1) != NULL);
+            return mp_obj_new_bool(find_subbytes(lhs_data, lhs_len, rhs_data, rhs_len, 1) != NULL);
 
         //case MP_BINARY_OP_NOT_EQUAL: // This is never passed here
         case MP_BINARY_OP_EQUAL: // This will be passed only for bytes, str is dealt with in mp_obj_equal()
@@ -368,7 +368,7 @@ mp_obj_t mp_obj_str_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_in) {
         case MP_BINARY_OP_LESS_EQUAL:
         case MP_BINARY_OP_MORE:
         case MP_BINARY_OP_MORE_EQUAL:
-            return MP_BOOL(mp_seq_cmp_bytes(op, lhs_data, lhs_len, rhs_data, rhs_len));
+            return mp_obj_new_bool(mp_seq_cmp_bytes(op, lhs_data, lhs_len, rhs_data, rhs_len));
     }
 
     return MP_OBJ_NULL; // op not supported
@@ -695,7 +695,7 @@ STATIC mp_obj_t str_startswith(mp_uint_t n_args, const mp_obj_t *args) {
     if (prefix_len + (start - str) > str_len) {
         return mp_const_false;
     }
-    return MP_BOOL(memcmp(start, prefix, prefix_len) == 0);
+    return mp_obj_new_bool(memcmp(start, prefix, prefix_len) == 0);
 }
 
 STATIC mp_obj_t str_endswith(mp_uint_t n_args, const mp_obj_t *args) {
@@ -708,7 +708,7 @@ STATIC mp_obj_t str_endswith(mp_uint_t n_args, const mp_obj_t *args) {
     if (suffix_len > str_len) {
         return mp_const_false;
     }
-    return MP_BOOL(memcmp(str + (str_len - suffix_len), suffix, suffix_len) == 0);
+    return mp_obj_new_bool(memcmp(str + (str_len - suffix_len), suffix, suffix_len) == 0);
 }
 
 enum { LSTRIP, RSTRIP, STRIP };
diff --git a/py/objstrunicode.c b/py/objstrunicode.c
index 1744925142..803b8014df 100644
--- a/py/objstrunicode.c
+++ b/py/objstrunicode.c
@@ -104,7 +104,7 @@ STATIC mp_obj_t uni_unary_op(mp_uint_t op, mp_obj_t self_in) {
     GET_STR_DATA_LEN(self_in, str_data, str_len);
     switch (op) {
         case MP_UNARY_OP_BOOL:
-            return MP_BOOL(str_len != 0);
+            return mp_obj_new_bool(str_len != 0);
         case MP_UNARY_OP_LEN:
             return MP_OBJ_NEW_SMALL_INT(unichar_charlen((const char *)str_data, str_len));
         default:
diff --git a/py/objtuple.c b/py/objtuple.c
index 9aac1ce4d6..305f273c6f 100644
--- a/py/objtuple.c
+++ b/py/objtuple.c
@@ -125,7 +125,7 @@ STATIC bool tuple_cmp_helper(mp_uint_t op, mp_obj_t self_in, mp_obj_t another_in
 mp_obj_t mp_obj_tuple_unary_op(mp_uint_t op, mp_obj_t self_in) {
     mp_obj_tuple_t *self = self_in;
     switch (op) {
-        case MP_UNARY_OP_BOOL: return MP_BOOL(self->len != 0);
+        case MP_UNARY_OP_BOOL: return mp_obj_new_bool(self->len != 0);
         case MP_UNARY_OP_HASH: {
             // start hash with pointer to empty tuple, to make it fairly unique
             mp_int_t hash = (mp_int_t)mp_const_empty_tuple;
@@ -168,7 +168,7 @@ mp_obj_t mp_obj_tuple_binary_op(mp_uint_t op, mp_obj_t lhs, mp_obj_t rhs) {
         case MP_BINARY_OP_LESS_EQUAL:
         case MP_BINARY_OP_MORE:
         case MP_BINARY_OP_MORE_EQUAL:
-            return MP_BOOL(tuple_cmp_helper(op, lhs, rhs));
+            return mp_obj_new_bool(tuple_cmp_helper(op, lhs, rhs));
 
         default:
             return MP_OBJ_NULL; // op not supported
diff --git a/py/runtime.c b/py/runtime.c
index 9c4fe7c723..4e055776b0 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -188,7 +188,7 @@ mp_obj_t mp_unary_op(mp_uint_t op, mp_obj_t arg) {
         mp_int_t val = MP_OBJ_SMALL_INT_VALUE(arg);
         switch (op) {
             case MP_UNARY_OP_BOOL:
-                return MP_BOOL(val != 0);
+                return mp_obj_new_bool(val != 0);
             case MP_UNARY_OP_HASH:
                 return arg;
             case MP_UNARY_OP_POSITIVE:
@@ -243,7 +243,7 @@ mp_obj_t mp_binary_op(mp_uint_t op, mp_obj_t lhs, mp_obj_t rhs) {
 
     // deal with is
     if (op == MP_BINARY_OP_IS) {
-        return MP_BOOL(lhs == rhs);
+        return mp_obj_new_bool(lhs == rhs);
     }
 
     // deal with == and != for all types
@@ -443,10 +443,10 @@ mp_obj_t mp_binary_op(mp_uint_t op, mp_obj_t lhs, mp_obj_t rhs) {
                     return tuple;
                 }
 
-                case MP_BINARY_OP_LESS: return MP_BOOL(lhs_val < rhs_val); break;
-                case MP_BINARY_OP_MORE: return MP_BOOL(lhs_val > rhs_val); break;
-                case MP_BINARY_OP_LESS_EQUAL: return MP_BOOL(lhs_val <= rhs_val); break;
-                case MP_BINARY_OP_MORE_EQUAL: return MP_BOOL(lhs_val >= rhs_val); break;
+                case MP_BINARY_OP_LESS: return mp_obj_new_bool(lhs_val < rhs_val); break;
+                case MP_BINARY_OP_MORE: return mp_obj_new_bool(lhs_val > rhs_val); break;
+                case MP_BINARY_OP_LESS_EQUAL: return mp_obj_new_bool(lhs_val <= rhs_val); break;
+                case MP_BINARY_OP_MORE_EQUAL: return mp_obj_new_bool(lhs_val >= rhs_val); break;
 
                 default:
                     goto unsupported_op;
diff --git a/stmhal/irq.c b/stmhal/irq.c
index d0d89b394f..7a265a52b9 100644
--- a/stmhal/irq.c
+++ b/stmhal/irq.c
@@ -48,7 +48,7 @@ MP_DEFINE_CONST_FUN_OBJ_0(pyb_wfi_obj, pyb_wfi);
 /// respectively.  This return value can be passed to enable_irq to restore
 /// the IRQ to its original state.
 STATIC mp_obj_t pyb_disable_irq(void) {
-    return MP_BOOL(disable_irq() == IRQ_STATE_ENABLED);
+    return mp_obj_new_bool(disable_irq() == IRQ_STATE_ENABLED);
 }
 MP_DEFINE_CONST_FUN_OBJ_0(pyb_disable_irq_obj, pyb_disable_irq);
 
diff --git a/stmhal/modnwcc3k.c b/stmhal/modnwcc3k.c
index 7dd5fb2cdf..20e7035e5b 100644
--- a/stmhal/modnwcc3k.c
+++ b/stmhal/modnwcc3k.c
@@ -512,7 +512,7 @@ STATIC mp_obj_t cc3k_disconnect(mp_obj_t self_in) {
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(cc3k_disconnect_obj, cc3k_disconnect);
 
 STATIC mp_obj_t cc3k_isconnected(mp_obj_t self_in) {
-    return MP_BOOL(wlan_connected && ip_obtained);
+    return mp_obj_new_bool(wlan_connected && ip_obtained);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(cc3k_isconnected_obj, cc3k_isconnected);
 
diff --git a/stmhal/pin.c b/stmhal/pin.c
index 8ba6cce8ea..9f40b11d67 100644
--- a/stmhal/pin.c
+++ b/stmhal/pin.c
@@ -305,7 +305,7 @@ STATIC mp_obj_t pin_debug(mp_uint_t n_args, const mp_obj_t *args) {
         pin_class_debug = mp_obj_is_true(args[1]);
         return mp_const_none;
     }
-    return MP_BOOL(pin_class_debug);
+    return mp_obj_new_bool(pin_class_debug);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pin_debug_fun_obj, 1, 2, pin_debug);
 STATIC MP_DEFINE_CONST_CLASSMETHOD_OBJ(pin_debug_obj, (mp_obj_t)&pin_debug_fun_obj);
diff --git a/stmhal/sdcard.c b/stmhal/sdcard.c
index 2e98f73c15..5d86ba5e6a 100644
--- a/stmhal/sdcard.c
+++ b/stmhal/sdcard.c
@@ -244,7 +244,7 @@ bool sdcard_write_blocks_dma(const uint8_t *src, uint32_t block_num, uint32_t nu
 // consistent interface and methods to mount/unmount it.
 
 STATIC mp_obj_t sd_present(mp_obj_t self) {
-    return MP_BOOL(sdcard_is_present());
+    return mp_obj_new_bool(sdcard_is_present());
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(sd_present_obj, sd_present);
 
@@ -256,7 +256,7 @@ STATIC mp_obj_t sd_power(mp_obj_t self, mp_obj_t state) {
         sdcard_power_off();
         result = true;
     }
-    return MP_BOOL(result);
+    return mp_obj_new_bool(result);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(sd_power_obj, sd_power);
 
diff --git a/stmhal/usb.c b/stmhal/usb.c
index cedd3525c7..ebd2433d26 100644
--- a/stmhal/usb.c
+++ b/stmhal/usb.c
@@ -363,7 +363,7 @@ STATIC mp_obj_t pyb_usb_vcp_setinterrupt(mp_obj_t self_in, mp_obj_t int_chr_in)
 STATIC MP_DEFINE_CONST_FUN_OBJ_2(pyb_usb_vcp_setinterrupt_obj, pyb_usb_vcp_setinterrupt);
 
 STATIC mp_obj_t pyb_usb_vcp_isconnected(mp_obj_t self_in) {
-    return MP_BOOL(USBD_CDC_IsConnected());
+    return mp_obj_new_bool(USBD_CDC_IsConnected());
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_usb_vcp_isconnected_obj, pyb_usb_vcp_isconnected);
 
diff --git a/teensy/modpyb.c b/teensy/modpyb.c
index a59e3b4f57..7a40580ed1 100644
--- a/teensy/modpyb.c
+++ b/teensy/modpyb.c
@@ -248,7 +248,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_0(pyb_standby_obj, pyb_standby);
 /// \function have_cdc()
 /// Return True if USB is connected as a serial device, False otherwise.
 STATIC mp_obj_t pyb_have_cdc(void ) {
-    return MP_BOOL(usb_vcp_is_connected());
+    return mp_obj_new_bool(usb_vcp_is_connected());
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_0(pyb_have_cdc_obj, pyb_have_cdc);
 
diff --git a/unix/modjni.c b/unix/modjni.c
index 0ffcb9969a..3946232615 100644
--- a/unix/modjni.c
+++ b/unix/modjni.c
@@ -265,7 +265,7 @@ STATIC mp_obj_t jobject_unary_op(mp_uint_t op, mp_obj_t self_in) {
         case MP_UNARY_OP_LEN: {
             jint len = JJ(CallIntMethod, self->obj, List_size_mid);
             if (op == MP_UNARY_OP_BOOL) {
-                return MP_BOOL(len != 0);
+                return mp_obj_new_bool(len != 0);
             }
             return MP_OBJ_NEW_SMALL_INT(len);
         }