diff --git a/src/nm-initrd-generator/nmi-cmdline-reader.c b/src/nm-initrd-generator/nmi-cmdline-reader.c
index a85013360d..249f53de41 100644
--- a/src/nm-initrd-generator/nmi-cmdline-reader.c
+++ b/src/nm-initrd-generator/nmi-cmdline-reader.c
@@ -443,6 +443,8 @@ reader_parse_ip(Reader *reader, const char *sysfs_dir, char *argument)
                          "on"
                          "any",
                          "dhcp6",
+                         "dhcp,dhcp6",
+                         "dhcp6,dhcp",
                          "auto",
                          "auto6",
                          "link6",
@@ -631,6 +633,16 @@ reader_parse_ip(Reader *reader, const char *sysfs_dir, char *argument)
                          NM_SETTING_IP4_CONFIG_METHOD_DISABLED,
                          NULL);
         }
+    } else if (NM_IN_STRSET(kind, "dhcp,dhcp6", "dhcp6,dhcp")) {
+        /* Both DHCPv4 and IPv6 autoconf are enabled, and
+         * each of them is tried for at least IP_REQUIRED_TIMEOUT_MSEC,
+         * even if the other one completes before.
+         */
+        clear_ip4_required_timeout = FALSE;
+        g_object_set(s_ip6,
+                     NM_SETTING_IP_CONFIG_REQUIRED_TIMEOUT,
+                     NMI_IP_REQUIRED_TIMEOUT_MSEC,
+                     NULL);
     } else if (nm_streq0(kind, "link6")) {
         g_object_set(s_ip6,
                      NM_SETTING_IP_CONFIG_METHOD,
diff --git a/src/nm-initrd-generator/tests/test-cmdline-reader.c b/src/nm-initrd-generator/tests/test-cmdline-reader.c
index e2a37c5835..e33918f98d 100644
--- a/src/nm-initrd-generator/tests/test-cmdline-reader.c
+++ b/src/nm-initrd-generator/tests/test-cmdline-reader.c
@@ -300,7 +300,7 @@ test_dhcp_timeout(void)
 static void
 test_if_auto_with_mtu(void)
 {
-    const char *const *ARGV                  = NM_MAKE_STRV("ip=eth0:auto:1666", "=");
+    const char *const *ARGV                  = NM_MAKE_STRV("ip=eth0:dhcp,dhcp6:1666", "=");
     gs_unref_object NMConnection *connection = NULL;
     NMSettingConnection *         s_con;
     NMSettingWired *              s_wired;
@@ -324,11 +324,17 @@ test_if_auto_with_mtu(void)
     g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip4), ==, NM_SETTING_IP4_CONFIG_METHOD_AUTO);
     g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip4));
     g_assert_cmpint(nm_setting_ip_config_get_dhcp_timeout(s_ip4), ==, 90);
+    g_assert_cmpint(nm_setting_ip_config_get_required_timeout(s_ip4),
+                    ==,
+                    NMI_IP_REQUIRED_TIMEOUT_MSEC);
 
     s_ip6 = nm_connection_get_setting_ip6_config(connection);
     g_assert(s_ip6);
     g_assert_cmpstr(nm_setting_ip_config_get_method(s_ip6), ==, NM_SETTING_IP6_CONFIG_METHOD_AUTO);
     g_assert(!nm_setting_ip_config_get_ignore_auto_dns(s_ip6));
+    g_assert_cmpint(nm_setting_ip_config_get_required_timeout(s_ip6),
+                    ==,
+                    NMI_IP_REQUIRED_TIMEOUT_MSEC);
 }
 
 static void