diff --git a/introspection/nm-device.xml b/introspection/nm-device.xml
index 950085c8b..c23b596c4 100644
--- a/introspection/nm-device.xml
+++ b/introspection/nm-device.xml
@@ -60,7 +60,7 @@
 
     <method name="Disconnect">
       <tp:docstring>
-        Manually disconnect a device
+        Disconnects a device and prevents the device from automatically activating further connections without user intervention.
       </tp:docstring>
       <annotation name="org.freedesktop.DBus.GLib.CSymbol" value="impl_device_disconnect"/>
     </method>
diff --git a/src/nm-device-interface.c b/src/nm-device-interface.c
index 60db27f2c..c8475df4c 100644
--- a/src/nm-device-interface.c
+++ b/src/nm-device-interface.c
@@ -53,6 +53,8 @@ nm_device_interface_error_get_type (void)
 			ENUM_ENTRY (NM_DEVICE_INTERFACE_ERROR_CONNECTION_ACTIVATING, "ConnectionActivating"),
 			/* Connection is invalid for this device. */
 			ENUM_ENTRY (NM_DEVICE_INTERFACE_ERROR_CONNECTION_INVALID, "ConnectionInvalid"),
+			/* Operation could not be performed because the device is not active. */
+			ENUM_ENTRY (NM_DEVICE_INTERFACE_ERROR_NOT_ACTIVE, "NotActive"),
 			{ 0, 0, 0 }
 		};
 		etype = g_enum_register_static ("NMDeviceInterfaceError", values);
@@ -277,12 +279,28 @@ gboolean
 nm_device_interface_disconnect (NMDeviceInterface *device,
                                 GError **error)
 {
-	g_return_val_if_fail (device, FALSE);
+	gboolean success = FALSE;
 
-	return NM_DEVICE_INTERFACE_GET_INTERFACE (device)->disconnect (device, error);
+	g_return_val_if_fail (NM_IS_DEVICE_INTERFACE (device), FALSE);
+
+	switch (nm_device_interface_get_state (device)) {
+	case NM_DEVICE_STATE_UNKNOWN:
+	case NM_DEVICE_STATE_UNMANAGED:
+	case NM_DEVICE_STATE_UNAVAILABLE:
+	case NM_DEVICE_STATE_DISCONNECTED:
+		g_set_error_literal (error,
+		                     NM_DEVICE_INTERFACE_ERROR,
+		                     NM_DEVICE_INTERFACE_ERROR_NOT_ACTIVE,
+		                     "Cannot disconnect an inactive device.");
+		break;
+	default:
+		success = NM_DEVICE_INTERFACE_GET_INTERFACE (device)->disconnect (device, error);
+		break;
+	}
+
+	return success;
 }
 
-
 static gboolean
 impl_device_disconnect (NMDeviceInterface *device,
                         GError **error)
diff --git a/src/nm-device-interface.h b/src/nm-device-interface.h
index ffa7e1c0e..0867bc292 100644
--- a/src/nm-device-interface.h
+++ b/src/nm-device-interface.h
@@ -36,6 +36,7 @@ typedef enum
 {
 	NM_DEVICE_INTERFACE_ERROR_CONNECTION_ACTIVATING = 0,
 	NM_DEVICE_INTERFACE_ERROR_CONNECTION_INVALID,
+	NM_DEVICE_INTERFACE_ERROR_NOT_ACTIVE,
 } NMDeviceInterfaceError;
 
 #define NM_DEVICE_INTERFACE_ERROR (nm_device_interface_error_quark ())
diff --git a/src/nm-device.c b/src/nm-device.c
index 155f689a1..d7e6e256c 100644
--- a/src/nm-device.c
+++ b/src/nm-device.c
@@ -2080,8 +2080,8 @@ device_disconnect (NMDeviceInterface *device,
                    GError **error)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (NM_DEVICE (device));
+
 	priv->autoconnect_inhibit = TRUE;	
-	nm_device_deactivate (device, NM_DEVICE_STATE_REASON_USER_REQUESTED);
 	nm_device_state_changed (NM_DEVICE (device), NM_DEVICE_STATE_DISCONNECTED, NM_DEVICE_STATE_REASON_USER_REQUESTED);
 	return TRUE;
 }