diff --git a/src/fprintd.h b/src/fprintd.h
index 2006f4b..c2743b3 100644
--- a/src/fprintd.h
+++ b/src/fprintd.h
@@ -43,6 +43,7 @@ typedef enum {
 	FPRINT_ERROR_NO_ENROLLED_PRINTS, /* No prints are enrolled */
 	FPRINT_ERROR_NO_ACTION_IN_PROGRESS, /* No actions currently in progress */
 	FPRINT_ERROR_INVALID_FINGERNAME, /* the finger name passed was invalid */
+	FPRINT_ERROR_NO_SUCH_DEVICE, /* device does not exist */
 } FprintError;
 
 /* Manager */
diff --git a/src/manager.c b/src/manager.c
index 4c88ed2..fdf2f16 100644
--- a/src/manager.c
+++ b/src/manager.c
@@ -185,6 +185,8 @@ static gboolean fprint_manager_get_default_device(FprintManager *manager,
 		*device = get_device_path (elem->data);
 		return TRUE;
 	} else {
+		g_set_error (error, FPRINT_ERROR, FPRINT_ERROR_NO_SUCH_DEVICE,
+			     "No devices available");
 		*device = NULL;
 		return FALSE;
 	}
@@ -214,6 +216,7 @@ fprint_error_get_type (void)
 			ENUM_ENTRY (FPRINT_ERROR_NO_ENROLLED_PRINTS, "NoEnrolledPrints"),
 			ENUM_ENTRY (FPRINT_ERROR_NO_ACTION_IN_PROGRESS, "NoActionInProgress"),
 			ENUM_ENTRY (FPRINT_ERROR_INVALID_FINGERNAME, "InvalidFingername"),
+			ENUM_ENTRY (FPRINT_ERROR_NO_SUCH_DEVICE, "NoSuchDevice"),
 			{ 0, 0, 0 }
 		};
 		etype = g_enum_register_static ("FprintError", values);
diff --git a/src/manager.xml b/src/manager.xml
index 76d289a..f4a38c7 100644
--- a/src/manager.xml
+++ b/src/manager.xml
@@ -1,4 +1,8 @@
-<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE node PUBLIC
+"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN"
+"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd" [
+<!ENTITY ERROR_NO_SUCH_DEVICE "net.reactivated.Fprint.Error.NoSuchDevice">
+]>
 <node name="/" xmlns:doc="http://www.freedesktop.org/dbus/1.0/doc.dtd">
 	<interface name="net.reactivated.Fprint.Manager">
 		<annotation name="org.freedesktop.DBus.GLib.CSymbol"
@@ -14,7 +18,8 @@
 			<doc:doc>
 				<doc:description>
 					<doc:para>
-						Enumerate all the fingerprint readers attached to the system.
+						Enumerate all the fingerprint readers attached to the system. If there are
+						no devices available, an empty array is returned.
 					</doc:para>
 				</doc:description>
 			</doc:doc>
@@ -33,6 +38,10 @@
 						Returns the default fingerprint reader device.
 					</doc:para>
 				</doc:description>
+
+				<doc:errors>
+					<doc:error name="&ERROR_NO_SUCH_DEVICE;">if the device does not exist</doc:error>
+				</doc:errors>
 			</doc:doc>
 		</method>