diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 9df4141016..24d8b3d415 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -7828,7 +7828,7 @@ generate_duid_from_machine_id (void)
 }
 
 static GBytes *
-dhcp6_get_duid (NMDevice *self, NMConnection *connection, GBytes *hwaddr, NMDhcpDuidEnforce *out_enforce)
+dhcp6_get_duid (NMDevice *self, NMConnection *connection, GBytes *hwaddr, gboolean *out_enforce)
 {
 	NMSettingIPConfig *s_ip6;
 	const char *duid;
@@ -7837,7 +7837,7 @@ dhcp6_get_duid (NMDevice *self, NMConnection *connection, GBytes *hwaddr, NMDhcp
 	GBytes *duid_out;
 	guint8 sha256_digest[32];
 	gsize len = sizeof (sha256_digest);
-	NMDhcpDuidEnforce duid_enforce = NM_DHCP_DUID_ENFORCE_ALWAYS;
+	gboolean duid_enforce = TRUE;
 	gs_free char *logstr1 = NULL;
 
 	s_ip6 = nm_connection_get_setting_ip6_config (connection);
@@ -7852,7 +7852,7 @@ dhcp6_get_duid (NMDevice *self, NMConnection *connection, GBytes *hwaddr, NMDhcp
 	}
 
 	if (nm_streq (duid, "lease")) {
-		duid_enforce = NM_DHCP_DUID_ENFORCE_NEVER;
+		duid_enforce = FALSE;
 		duid_out = generate_duid_from_machine_id ();
 		if (!duid_out) {
 			duid_error = "failure to read machine-id";
@@ -7972,7 +7972,7 @@ out_good:
 	       "ipv6.dhcp-duid: generate %s DUID '%s' (%s)",
 	       duid,
 	       (logstr1 = nm_dhcp_utils_duid_to_string (duid_out)),
-	       (duid_enforce == NM_DHCP_DUID_ENFORCE_ALWAYS) ? "enforcing" : "fallback");
+	       duid_enforce ? "enforcing" : "prefer lease");
 
 	NM_SET_OUT (out_enforce, duid_enforce);
 	return duid_out;
@@ -7985,7 +7985,7 @@ dhcp6_start_with_link_ready (NMDevice *self, NMConnection *connection)
 	NMSettingIPConfig *s_ip6;
 	gs_unref_bytes GBytes *hwaddr = NULL;
 	gs_unref_bytes GBytes *duid = NULL;
-	NMDhcpDuidEnforce enforce_duid = NM_DHCP_DUID_ENFORCE_NEVER;
+	gboolean enforce_duid = FALSE;
 
 	const NMPlatformIP6Address *ll_addr = NULL;
 
diff --git a/src/dhcp/nm-dhcp-client.c b/src/dhcp/nm-dhcp-client.c
index 390b7054ec..360bd36767 100644
--- a/src/dhcp/nm-dhcp-client.c
+++ b/src/dhcp/nm-dhcp-client.c
@@ -513,7 +513,7 @@ nm_dhcp_client_start_ip4 (NMDhcpClient *self,
 }
 
 static GBytes *
-get_duid (NMDhcpClient *self, gboolean global)
+get_duid (NMDhcpClient *self)
 {
 	return NULL;
 }
@@ -521,7 +521,7 @@ get_duid (NMDhcpClient *self, gboolean global)
 gboolean
 nm_dhcp_client_start_ip6 (NMDhcpClient *self,
                           GBytes *client_id,
-                          NMDhcpDuidEnforce enforce_duid,
+                          gboolean enforce_duid,
                           const char *dhcp_anycast_addr,
                           const struct in6_addr *ll_addr,
                           const char *hostname,
@@ -541,12 +541,9 @@ nm_dhcp_client_start_ip6 (NMDhcpClient *self,
 	nm_assert (!priv->duid);
 	nm_assert (client_id);
 
-	if (enforce_duid == NM_DHCP_DUID_ENFORCE_NEVER)
-		priv->duid = NM_DHCP_CLIENT_GET_CLASS (self)->get_duid (self, TRUE);
-	else if (enforce_duid == NM_DHCP_DUID_ENFORCE_LEASE_FALLBACK)
-		priv->duid = NM_DHCP_CLIENT_GET_CLASS (self)->get_duid (self, FALSE);
+	if (!enforce_duid)
+		priv->duid = NM_DHCP_CLIENT_GET_CLASS (self)->get_duid (self);
 
-	/* NM_DHCP_DUID_ENFORCE_ALWAYS and fallback */
 	if (!priv->duid)
 		priv->duid = g_bytes_ref (client_id);
 
diff --git a/src/dhcp/nm-dhcp-client.h b/src/dhcp/nm-dhcp-client.h
index 98c3ed262e..f3d0b7d184 100644
--- a/src/dhcp/nm-dhcp-client.h
+++ b/src/dhcp/nm-dhcp-client.h
@@ -96,15 +96,13 @@ typedef struct {
 	/**
 	 * get_duid:
 	 * @self: the #NMDhcpClient
-	 * @global: if set to #true, the duid should be searched also in the
-	 *          DHCP client's system-wide persistent configuration.
 	 *
 	 * Attempts to find an existing DHCPv6 DUID for this client in the DHCP
 	 * client's persistent configuration.  Returned DUID should be the binary
 	 * representation of the DUID.  If no DUID is found, %NULL should be
 	 * returned.
 	 */
-	GBytes *(*get_duid) (NMDhcpClient *self, gboolean global);
+	GBytes *(*get_duid) (NMDhcpClient *self);
 
 	/* Signals */
 	void (*state_changed) (NMDhcpClient *self,
@@ -153,7 +151,7 @@ gboolean nm_dhcp_client_start_ip4 (NMDhcpClient *self,
 
 gboolean nm_dhcp_client_start_ip6 (NMDhcpClient *self,
                                    GBytes *client_id,
-                                   NMDhcpDuidEnforce enforce_duid,
+                                   gboolean enforce_duid,
                                    const char *dhcp_anycast_addr,
                                    const struct in6_addr *ll_addr,
                                    const char *hostname,
diff --git a/src/dhcp/nm-dhcp-dhclient.c b/src/dhcp/nm-dhcp-dhclient.c
index 43746dd394..3bd14ebe89 100644
--- a/src/dhcp/nm-dhcp-dhclient.c
+++ b/src/dhcp/nm-dhcp-dhclient.c
@@ -582,7 +582,7 @@ state_changed (NMDhcpClient *client,
 }
 
 static GBytes *
-get_duid (NMDhcpClient *client, gboolean global)
+get_duid (NMDhcpClient *client)
 {
 	NMDhcpDhclient *self = NM_DHCP_DHCLIENT (client);
 	NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE (self);
@@ -607,7 +607,7 @@ get_duid (NMDhcpClient *client, gboolean global)
 		g_free (leasefile);
 	}
 
-	if (!duid && global) {
+	if (!duid) {
 		/* Otherwise read the default machine-wide DUID */
 		_LOGD ("looking for default DUID in '%s'", priv->def_leasefile);
 		duid = nm_dhcp_dhclient_read_duid (priv->def_leasefile, &error);
diff --git a/src/dhcp/nm-dhcp-manager.c b/src/dhcp/nm-dhcp-manager.c
index 2d85c73ac7..672543237e 100644
--- a/src/dhcp/nm-dhcp-manager.c
+++ b/src/dhcp/nm-dhcp-manager.c
@@ -164,7 +164,7 @@ client_start (NMDhcpManager *self,
               guint32 route_metric,
               const struct in6_addr *ipv6_ll_addr,
               GBytes *dhcp_client_id,
-              NMDhcpDuidEnforce enforce_duid,
+              gboolean enforce_duid,
               guint32 timeout,
               const char *dhcp_anycast_addr,
               const char *hostname,
@@ -299,7 +299,7 @@ nm_dhcp_manager_start_ip6 (NMDhcpManager *self,
                            gboolean send_hostname,
                            const char *dhcp_hostname,
                            GBytes *duid,
-                           NMDhcpDuidEnforce enforce_duid,
+                           gboolean enforce_duid,
                            guint32 timeout,
                            const char *dhcp_anycast_addr,
                            gboolean info_only,
diff --git a/src/dhcp/nm-dhcp-manager.h b/src/dhcp/nm-dhcp-manager.h
index ed8ee742a9..7eb32c37da 100644
--- a/src/dhcp/nm-dhcp-manager.h
+++ b/src/dhcp/nm-dhcp-manager.h
@@ -73,7 +73,7 @@ NMDhcpClient * nm_dhcp_manager_start_ip6     (NMDhcpManager *manager,
                                               gboolean send_hostname,
                                               const char *dhcp_hostname,
                                               GBytes *duid,
-                                              NMDhcpDuidEnforce enforce_duid,
+                                              gboolean enforce_duid,
                                               guint32 timeout,
                                               const char *dhcp_anycast_addr,
                                               gboolean info_only,
diff --git a/src/dhcp/nm-dhcp-utils.h b/src/dhcp/nm-dhcp-utils.h
index afb87c1a14..5c127bd194 100644
--- a/src/dhcp/nm-dhcp-utils.h
+++ b/src/dhcp/nm-dhcp-utils.h
@@ -24,12 +24,6 @@
 #include "nm-ip4-config.h"
 #include "nm-ip6-config.h"
 
-typedef enum {
-	NM_DHCP_DUID_ENFORCE_NEVER = 0,
-	NM_DHCP_DUID_ENFORCE_LEASE_FALLBACK,
-	NM_DHCP_DUID_ENFORCE_ALWAYS,
-} NMDhcpDuidEnforce;
-
 NMIP4Config *nm_dhcp_utils_ip4_config_from_options (struct _NMDedupMultiIndex *multi_idx,
                                                     int ifindex,
                                                     const char *iface,