diff --git a/py/runtime.c b/py/runtime.c
index 8df0c0a080..41f2f6976e 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -669,7 +669,7 @@ void mp_call_prepare_args_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_
 
         // allocate memory for the new array of args
         args2_alloc = 1 + n_args + 2 * (n_kw + kw_dict_len);
-        args2 = m_new(mp_obj_t, args2_alloc);
+        args2 = mp_nonlocal_alloc(args2_alloc * sizeof(mp_obj_t));
 
         // copy the self
         if (self != MP_OBJ_NULL) {
@@ -690,7 +690,7 @@ void mp_call_prepare_args_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_
 
         // allocate memory for the new array of args
         args2_alloc = 1 + n_args + len + 2 * (n_kw + kw_dict_len);
-        args2 = m_new(mp_obj_t, args2_alloc);
+        args2 = mp_nonlocal_alloc(args2_alloc * sizeof(mp_obj_t));
 
         // copy the self
         if (self != MP_OBJ_NULL) {
@@ -706,7 +706,7 @@ void mp_call_prepare_args_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_
 
         // allocate memory for the new array of args
         args2_alloc = 1 + n_args + 2 * (n_kw + kw_dict_len) + 3;
-        args2 = m_new(mp_obj_t, args2_alloc);
+        args2 = mp_nonlocal_alloc(args2_alloc * sizeof(mp_obj_t));
 
         // copy the self
         if (self != MP_OBJ_NULL) {
@@ -723,7 +723,7 @@ void mp_call_prepare_args_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_
         mp_obj_t item;
         while ((item = mp_iternext(iterable)) != MP_OBJ_STOP_ITERATION) {
             if (args2_len >= args2_alloc) {
-                args2 = m_renew(mp_obj_t, args2, args2_alloc, args2_alloc * 2);
+                args2 = mp_nonlocal_realloc(args2, args2_alloc * sizeof(mp_obj_t), args2_alloc * 2 * sizeof(mp_obj_t));
                 args2_alloc *= 2;
             }
             args2[args2_len++] = item;
@@ -774,7 +774,7 @@ void mp_call_prepare_args_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_
                 if (new_alloc < 4) {
                     new_alloc = 4;
                 }
-                args2 = m_renew(mp_obj_t, args2, args2_alloc, new_alloc);
+                args2 = mp_nonlocal_realloc(args2, args2_alloc * sizeof(mp_obj_t), new_alloc * sizeof(mp_obj_t));
                 args2_alloc = new_alloc;
             }
 
@@ -806,7 +806,7 @@ mp_obj_t mp_call_method_n_kw_var(bool have_self, size_t n_args_n_kw, const mp_ob
     mp_call_prepare_args_n_kw_var(have_self, n_args_n_kw, args, &out_args);
 
     mp_obj_t res = mp_call_function_n_kw(out_args.fun, out_args.n_args, out_args.n_kw, out_args.args);
-    m_del(mp_obj_t, out_args.args, out_args.n_alloc);
+    mp_nonlocal_free(out_args.args, out_args.n_alloc * sizeof(mp_obj_t));
 
     return res;
 }
diff --git a/py/vm.c b/py/vm.c
index a8a73f3239..b18a2b5e32 100644
--- a/py/vm.c
+++ b/py/vm.c
@@ -966,7 +966,11 @@ unwind_jump:;
 
                         mp_code_state_t *new_state = mp_obj_fun_bc_prepare_codestate(out_args.fun,
                             out_args.n_args, out_args.n_kw, out_args.args);
-                        m_del(mp_obj_t, out_args.args, out_args.n_alloc);
+                        #if !MICROPY_ENABLE_PYSTACK
+                        // Freeing args at this point does not follow a LIFO order so only do it if
+                        // pystack is not enabled.  For pystack, they are freed when code_state is.
+                        mp_nonlocal_free(out_args.args, out_args.n_alloc * sizeof(mp_obj_t));
+                        #endif
                         if (new_state) {
                             new_state->prev = code_state;
                             code_state = new_state;
@@ -1043,7 +1047,11 @@ unwind_jump:;
 
                         mp_code_state_t *new_state = mp_obj_fun_bc_prepare_codestate(out_args.fun,
                             out_args.n_args, out_args.n_kw, out_args.args);
-                        m_del(mp_obj_t, out_args.args, out_args.n_alloc);
+                        #if !MICROPY_ENABLE_PYSTACK
+                        // Freeing args at this point does not follow a LIFO order so only do it if
+                        // pystack is not enabled.  For pystack, they are freed when code_state is.
+                        mp_nonlocal_free(out_args.args, out_args.n_alloc * sizeof(mp_obj_t));
+                        #endif
                         if (new_state) {
                             new_state->prev = code_state;
                             code_state = new_state;
@@ -1110,6 +1118,8 @@ unwind_return:
                         mp_globals_set(code_state->old_globals);
                         mp_code_state_t *new_code_state = code_state->prev;
                         #if MICROPY_ENABLE_PYSTACK
+                        // Free code_state, and args allocated by mp_call_prepare_args_n_kw_var
+                        // (The latter is implicitly freed when using pystack due to its LIFO nature.)
                         // The sizeof in the following statement does not include the size of the variable
                         // part of the struct.  This arg is anyway not used if pystack is enabled.
                         mp_nonlocal_free(code_state, sizeof(mp_code_state_t));
@@ -1458,6 +1468,8 @@ unwind_loop:
                 mp_globals_set(code_state->old_globals);
                 mp_code_state_t *new_code_state = code_state->prev;
                 #if MICROPY_ENABLE_PYSTACK
+                // Free code_state, and args allocated by mp_call_prepare_args_n_kw_var
+                // (The latter is implicitly freed when using pystack due to its LIFO nature.)
                 // The sizeof in the following statement does not include the size of the variable
                 // part of the struct.  This arg is anyway not used if pystack is enabled.
                 mp_nonlocal_free(code_state, sizeof(mp_code_state_t));