diff --git a/cli/mmcli-modem.c b/cli/mmcli-modem.c
index 981421b6..154414b9 100644
--- a/cli/mmcli-modem.c
+++ b/cli/mmcli-modem.c
@@ -323,10 +323,12 @@ print_modem_info (void)
     g_print ("  -------------------------\n"
              "  System   |         device: '%s'\n"
              "           |        drivers: '%s'\n"
-             "           |         plugin: '%s'\n",
+             "           |         plugin: '%s'\n"
+             "           |   primary port: '%s'\n",
              VALIDATE_UNKNOWN (mm_modem_get_device (ctx->modem)),
              VALIDATE_UNKNOWN (drivers_string),
-             VALIDATE_UNKNOWN (mm_modem_get_plugin (ctx->modem)));
+             VALIDATE_UNKNOWN (mm_modem_get_plugin (ctx->modem)),
+             VALIDATE_UNKNOWN (mm_modem_get_primary_port (ctx->modem)));
 
     /* Numbers related stuff */
     g_print ("  -------------------------\n"
diff --git a/docs/reference/libmm-glib/libmm-glib-sections.txt b/docs/reference/libmm-glib/libmm-glib-sections.txt
index 181d6604..f37e7a3d 100644
--- a/docs/reference/libmm-glib/libmm-glib-sections.txt
+++ b/docs/reference/libmm-glib/libmm-glib-sections.txt
@@ -89,6 +89,8 @@ mm_modem_get_drivers
 mm_modem_dup_drivers
 mm_modem_get_plugin
 mm_modem_dup_plugin
+mm_modem_get_primary_port
+mm_modem_dup_primary_port
 mm_modem_get_device
 mm_modem_dup_device
 mm_modem_get_equipment_identifier
@@ -1389,6 +1391,8 @@ mm_gdbus_modem_get_own_numbers
 mm_gdbus_modem_dup_own_numbers
 mm_gdbus_modem_get_plugin
 mm_gdbus_modem_dup_plugin
+mm_gdbus_modem_get_primary_port
+mm_gdbus_modem_dup_primary_port
 mm_gdbus_modem_get_preferred_mode
 mm_gdbus_modem_get_revision
 mm_gdbus_modem_dup_revision
@@ -1447,6 +1451,7 @@ mm_gdbus_modem_set_model
 mm_gdbus_modem_set_modem_capabilities
 mm_gdbus_modem_set_own_numbers
 mm_gdbus_modem_set_plugin
+mm_gdbus_modem_set_primary_port
 mm_gdbus_modem_set_preferred_mode
 mm_gdbus_modem_set_revision
 mm_gdbus_modem_set_signal_quality
diff --git a/introspection/org.freedesktop.ModemManager1.Modem.xml b/introspection/org.freedesktop.ModemManager1.Modem.xml
index 06c4116b..9a1a5126 100644
--- a/introspection/org.freedesktop.ModemManager1.Modem.xml
+++ b/introspection/org.freedesktop.ModemManager1.Modem.xml
@@ -296,6 +296,13 @@
     -->
     <property name="Plugin" type="s" access="read" />
 
+    <!--
+        PrimaryPort:
+
+        The name of the primary port using to control the modem.
+    -->
+    <property name="PrimaryPort" type="s" access="read" />
+
     <!--
         EquipmentIdentifier:
 
diff --git a/libmm-glib/mm-modem.c b/libmm-glib/mm-modem.c
index 6b9357a0..b575a300 100644
--- a/libmm-glib/mm-modem.c
+++ b/libmm-glib/mm-modem.c
@@ -537,6 +537,47 @@ mm_modem_dup_plugin (MMModem *self)
 
 /*****************************************************************************/
 
+/**
+ * mm_modem_get_primary_port:
+ * @self: A #MMModem.
+ *
+ * Gets the name of the primary port controlling this #MMModem.
+ *
+ * <warning>The returned value is only valid until the property changes so
+ * it is only safe to use this function on the thread where
+ * @self was constructed. Use mm_modem_dup_primary_port() if on another
+ * thread.</warning>
+ *
+ * Returns: (transfer none): The name of the primary port. Do not free the returned value, it belongs to @self.
+ */
+const gchar *
+mm_modem_get_primary_port (MMModem *self)
+{
+    g_return_val_if_fail (MM_IS_MODEM (self), NULL);
+
+    RETURN_NON_EMPTY_CONSTANT_STRING (
+        mm_gdbus_modem_get_primary_port (MM_GDBUS_MODEM (self)));
+}
+
+/**
+ * mm_modem_dup_primary_port:
+ * @self: A #MMModem.
+ *
+ * Gets a copy of the name of the primary port controlling this #MMModem.
+ *
+ * Returns: (transfer full): The name of the primary port. The returned value should be freed with g_free().
+ */
+gchar *
+mm_modem_dup_primary_port (MMModem *self)
+{
+    g_return_val_if_fail (MM_IS_MODEM (self), NULL);
+
+    RETURN_NON_EMPTY_STRING (
+        mm_gdbus_modem_dup_primary_port (MM_GDBUS_MODEM (self)));
+}
+
+/*****************************************************************************/
+
 /**
  * mm_modem_get_equipment_identifier:
  * @self: A #MMModem.
diff --git a/libmm-glib/mm-modem.h b/libmm-glib/mm-modem.h
index 480c3fe4..46609ca4 100644
--- a/libmm-glib/mm-modem.h
+++ b/libmm-glib/mm-modem.h
@@ -102,6 +102,9 @@ gchar               **mm_modem_dup_drivers           (MMModem *self);
 const gchar       *mm_modem_get_plugin               (MMModem *self);
 gchar             *mm_modem_dup_plugin               (MMModem *self);
 
+const gchar       *mm_modem_get_primary_port         (MMModem *self);
+gchar             *mm_modem_dup_primary_port         (MMModem *self);
+
 const gchar       *mm_modem_get_equipment_identifier (MMModem *self);
 gchar             *mm_modem_dup_equipment_identifier (MMModem *self);
 
diff --git a/src/mm-iface-modem.c b/src/mm-iface-modem.c
index 4222dda6..68b6ba55 100644
--- a/src/mm-iface-modem.c
+++ b/src/mm-iface-modem.c
@@ -3328,6 +3328,21 @@ interface_initialization_step (InitializationContext *ctx)
             mm_gdbus_modem_set_plugin (ctx->skeleton, plugin);
             g_free (plugin);
         }
+        /* Load primary port if not done before */
+        if (!mm_gdbus_modem_get_primary_port (ctx->skeleton)) {
+            MMPort *primary;
+
+#if defined WITH_QMI
+            primary = MM_PORT (mm_base_modem_peek_port_qmi (MM_BASE_MODEM (ctx->self)));
+            if (!primary)
+                primary = MM_PORT (mm_base_modem_peek_port_primary (MM_BASE_MODEM (ctx->self)));
+#else
+            primary = MM_PORT (mm_base_modem_peek_port_primary (MM_BASE_MODEM (ctx->self)));
+#endif
+
+            g_assert (primary != NULL);
+            mm_gdbus_modem_set_primary_port (ctx->skeleton, mm_port_get_device (primary));
+        }
         /* Fall down to next step */
         ctx->step++;