diff --git a/py/obj.h b/py/obj.h
index 93d1e0ee34..0736252247 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -371,25 +371,25 @@ typedef struct _mp_rom_obj_t { mp_const_obj_t o; } mp_rom_obj_t;
 
 #define MP_DEFINE_CONST_FUN_OBJ_0(obj_name, fun_name) \
     const mp_obj_fun_builtin_fixed_t obj_name = \
-    {{&mp_type_fun_builtin_0}, .fun._0 = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_0}, .fun = {._0 = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_1(obj_name, fun_name) \
     const mp_obj_fun_builtin_fixed_t obj_name = \
-    {{&mp_type_fun_builtin_1}, .fun._1 = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_1}, .fun = {._1 = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_2(obj_name, fun_name) \
     const mp_obj_fun_builtin_fixed_t obj_name = \
-    {{&mp_type_fun_builtin_2}, .fun._2 = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_2}, .fun = {._2 = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_3(obj_name, fun_name) \
     const mp_obj_fun_builtin_fixed_t obj_name = \
-    {{&mp_type_fun_builtin_3}, .fun._3 = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_3}, .fun = {._3 = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_VAR(obj_name, n_args_min, fun_name) \
     const mp_obj_fun_builtin_var_t obj_name = \
-    {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, false), .fun.var = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_var}, .sig = MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, false), .fun = {.var = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(obj_name, n_args_min, n_args_max, fun_name) \
     const mp_obj_fun_builtin_var_t obj_name = \
-    {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, false), .fun.var = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_var}, .sig = MP_OBJ_FUN_MAKE_SIG(n_args_min, n_args_max, false), .fun = {.var = fun_name}}
 #define MP_DEFINE_CONST_FUN_OBJ_KW(obj_name, n_args_min, fun_name) \
     const mp_obj_fun_builtin_var_t obj_name = \
-    {{&mp_type_fun_builtin_var}, MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun.kw = fun_name}
+    {.base = {.type = &mp_type_fun_builtin_var}, .sig = MP_OBJ_FUN_MAKE_SIG(n_args_min, MP_OBJ_FUN_ARGS_MAX, true), .fun = {.kw = fun_name}}
 
 // These macros are used to define constant map/dict objects
 // You can put "static" in front of the definition to make it local
diff --git a/py/objtuple.h b/py/objtuple.h
index 034814b826..3c82a9edcf 100644
--- a/py/objtuple.h
+++ b/py/objtuple.h
@@ -50,7 +50,7 @@ extern const mp_obj_type_t mp_type_attrtuple;
 
 #define MP_DEFINE_ATTRTUPLE(tuple_obj_name, fields, nitems, ...) \
     const mp_rom_obj_tuple_t tuple_obj_name = { \
-        .base = {&mp_type_attrtuple}, \
+        .base = {.type = &mp_type_attrtuple}, \
         .len = nitems, \
         .items = { __VA_ARGS__, MP_ROM_PTR((void *)fields) } \
     }
diff --git a/py/runtime.h b/py/runtime.h
index e8e5a758f8..77cdd0e203 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -30,12 +30,12 @@
 #include "py/pystack.h"
 #include "py/cstack.h"
 
-// For use with mp_call_function_1_from_nlr_jump_callback.
+// Initialize an nlr_jump_callback_node_call_function_1_t struct for use with
+// nlr_push_jump_callback(&ctx.callback, mp_call_function_1_from_nlr_jump_callback);
 #define MP_DEFINE_NLR_JUMP_CALLBACK_FUNCTION_1(ctx, f, a) \
-    nlr_jump_callback_node_call_function_1_t ctx = { \
-        .func = (void (*)(void *))(f), \
-        .arg = (a), \
-    }
+    nlr_jump_callback_node_call_function_1_t ctx; \
+    ctx.func = (void (*)(void *))(f); \
+    ctx.arg = (a)
 
 typedef enum {
     MP_VM_RETURN_NORMAL,