diff --git a/src/core/nm-policy.c b/src/core/nm-policy.c
index 5999bc0590..f13282c482 100644
--- a/src/core/nm-policy.c
+++ b/src/core/nm-policy.c
@@ -331,9 +331,8 @@ device_ip6_prefix_delegated(NMDevice                   *device,
 
     if (i == priv->ip6_prefix_delegations->len) {
         /* Allocate a delegation for new prefix. */
-        g_array_set_size(priv->ip6_prefix_delegations, i + 1);
-        delegation          = &g_array_index(priv->ip6_prefix_delegations, IP6PrefixDelegation, i);
-        delegation->subnets = g_hash_table_new(nm_direct_hash, NULL);
+        delegation = nm_g_array_append_new(priv->ip6_prefix_delegations, IP6PrefixDelegation);
+        delegation->subnets     = g_hash_table_new(nm_direct_hash, NULL);
         delegation->next_subnet = 0;
     }
 
diff --git a/src/core/platform/nm-fake-platform.c b/src/core/platform/nm-fake-platform.c
index c0680fb10f..70c8664666 100644
--- a/src/core/platform/nm-fake-platform.c
+++ b/src/core/platform/nm-fake-platform.c
@@ -234,8 +234,7 @@ link_add_pre(NMPlatform *platform,
 
     g_assert(!name || strlen(name) < IFNAMSIZ);
 
-    g_array_set_size(priv->links, priv->links->len + 1);
-    device  = &g_array_index(priv->links, NMFakePlatformLink, priv->links->len - 1);
+    device  = nm_g_array_append_new(priv->links, NMFakePlatformLink);
     ifindex = priv->links->len;
 
     memset(device, 0, sizeof(*device));
diff --git a/src/libnm-core-impl/nm-setting.c b/src/libnm-core-impl/nm-setting.c
index 35070baed1..8e975b64bd 100644
--- a/src/libnm-core-impl/nm-setting.c
+++ b/src/libnm-core-impl/nm-setting.c
@@ -360,8 +360,7 @@ _nm_setting_class_commit(NMSettingClass             *setting_class,
                                                  name))
             continue;
 
-        g_array_set_size(properties_override, properties_override->len + 1);
-        p = &g_array_index(properties_override, NMSettInfoProperty, properties_override->len - 1);
+        p = nm_g_array_append_new(properties_override, NMSettInfoProperty);
         memset(p, 0, sizeof(*p));
         p->name       = name;
         p->param_spec = property_specs[i];
diff --git a/src/libnm-core-impl/nm-utils.c b/src/libnm-core-impl/nm-utils.c
index b6e57de144..9a7167f67f 100644
--- a/src/libnm-core-impl/nm-utils.c
+++ b/src/libnm-core-impl/nm-utils.c
@@ -4247,13 +4247,13 @@ _nm_utils_generate_mac_address_mask_parse(const char         *value,
         ouis = g_array_sized_new(FALSE, FALSE, sizeof(struct ether_addr), 4);
 
         do {
+            struct ether_addr *new;
+
             s      = s_next;
             s_next = _split_word(s);
 
-            g_array_set_size(ouis, ouis->len + 1);
-            if (!nm_utils_hwaddr_aton(s,
-                                      &g_array_index(ouis, struct ether_addr, ouis->len - 1),
-                                      ETH_ALEN)) {
+            new = nm_g_array_append_new(ouis, struct ether_addr);
+            if (!nm_utils_hwaddr_aton(s, new, ETH_ALEN)) {
                 g_set_error(error,
                             NM_UTILS_ERROR,
                             NM_UTILS_ERROR_UNKNOWN,
diff --git a/src/libnm-platform/nm-linux-platform.c b/src/libnm-platform/nm-linux-platform.c
index 3cbb6a685d..03725b2558 100644
--- a/src/libnm-platform/nm-linux-platform.c
+++ b/src/libnm-platform/nm-linux-platform.c
@@ -2541,16 +2541,15 @@ _wireguard_update_from_peers_nla(CList *peers, GArray **p_allowed_ips, struct nl
         GArray        *allowed_ips = *p_allowed_ips;
 
         nla_for_each_nested (attr, tb[WGPEER_A_ALLOWEDIPS], rem) {
+            NMPWireGuardAllowedIP *new;
+
             if (!allowed_ips) {
                 allowed_ips    = g_array_new(FALSE, FALSE, sizeof(NMPWireGuardAllowedIP));
                 *p_allowed_ips = allowed_ips;
-                g_array_set_size(allowed_ips, 1);
-            } else
-                g_array_set_size(allowed_ips, allowed_ips->len + 1);
+            }
 
-            if (!_wireguard_update_from_allowed_ips_nla(
-                    &g_array_index(allowed_ips, NMPWireGuardAllowedIP, allowed_ips->len - 1),
-                    attr)) {
+            new = nm_g_array_append_new(allowed_ips, NMPWireGuardAllowedIP);
+            if (!_wireguard_update_from_allowed_ips_nla(new, attr)) {
                 /* we ignore the error of parsing one allowed-ip. */
                 g_array_set_size(allowed_ips, allowed_ips->len - 1);
                 continue;
diff --git a/src/libnm-platform/nmp-netns.c b/src/libnm-platform/nmp-netns.c
index 2563e8f640..b3e2e043c0 100644
--- a/src/libnm-platform/nmp-netns.c
+++ b/src/libnm-platform/nmp-netns.c
@@ -262,9 +262,7 @@ _stack_push(GArray *netns_stack, NMPNetns *netns, int ns_types)
     nm_assert(NM_FLAGS_ANY(ns_types, _CLONE_NS_ALL));
     nm_assert(!NM_FLAGS_ANY(ns_types, ~_CLONE_NS_ALL));
 
-    g_array_set_size(netns_stack, netns_stack->len + 1);
-
-    info  = &g_array_index(netns_stack, NetnsInfo, (netns_stack->len - 1));
+    info  = nm_g_array_append_new(netns_stack, NetnsInfo);
     *info = (NetnsInfo){
         .netns    = g_object_ref(netns),
         .ns_types = ns_types,