diff --git a/libupower-glib/up-device.c b/libupower-glib/up-device.c
index 1773f1d..866b8c6 100644
--- a/libupower-glib/up-device.c
+++ b/libupower-glib/up-device.c
@@ -499,7 +499,8 @@ up_device_get_history_sync (UpDevice *device, const gchar *type, guint timespec,
 							NULL,
 							&error_local);
 	if (!ret) {
-		g_set_error (error, 1, 0, "GetHistory(%s,%i) on %s failed: %s", type, timespec,
+		if (error_local->message)
+			g_set_error (error, 1, 0, "GetHistory(%s,%i) on %s failed: %s", type, timespec,
 			     up_device_get_object_path (device), error_local->message);
 		g_error_free (error_local);
 		goto out;
@@ -576,7 +577,8 @@ up_device_get_statistics_sync (UpDevice *device, const gchar *type, GCancellable
 							   NULL,
 							   &error_local);
 	if (!ret) {
-		g_set_error (error, 1, 0, "GetStatistics(%s) on %s failed: %s", type,
+		if (error_local->message)
+			g_set_error (error, 1, 0, "GetStatistics(%s) on %s failed: %s", type,
 				      up_device_get_object_path (device), error_local->message);
 		g_error_free (error_local);
 		goto out;
diff --git a/src/linux/up-device-wup.c b/src/linux/up-device-wup.c
index 3adbaa7..fcbc46e 100644
--- a/src/linux/up-device-wup.c
+++ b/src/linux/up-device-wup.c
@@ -324,7 +324,8 @@ up_device_wup_coldplug (UpDevice *device)
 
 	/* dummy read */
 	data = up_device_wup_read_command (wup);
-	g_debug ("data after clear %s", data);
+	if (data)
+		g_debug ("data after clear %s", data);
 
 	/* shouldn't do anything */
 	up_device_wup_parse_command (wup, data);
diff --git a/src/linux/up-enumerator-udev.c b/src/linux/up-enumerator-udev.c
index e1b0456..99723a8 100644
--- a/src/linux/up-enumerator-udev.c
+++ b/src/linux/up-enumerator-udev.c
@@ -240,8 +240,8 @@ power_supply_add_helper (UpEnumeratorUdev  *self,
 
 	/* Fire relevant sibling events and insert into lookup table */
 	parent_id = device_parent_id (device);
-	g_debug ("device %s has parent id: %s", device_key, parent_id);
 	if (parent_id) {
+		g_debug ("device %s has parent id: %s", device_key, parent_id);
 		GPtrArray *devices = NULL;
 		char *parent_id_key = NULL;
 		int i;
diff --git a/src/linux/up-input.c b/src/linux/up-input.c
index db96a9e..7592ce6 100644
--- a/src/linux/up-input.c
+++ b/src/linux/up-input.c
@@ -222,7 +222,8 @@ up_input_coldplug (UpInput *input, GUdevDevice *d)
 	/* convert to a bitmask */
 	num_bits = up_input_str_to_bitmask (contents, bitmask, sizeof (bitmask));
 	if ((num_bits == 0) || (num_bits >= SW_CNT)) {
-		g_debug ("invalid bitmask entry for %s", native_path);
+		if (native_path)
+			g_debug ("invalid bitmask entry for %s", native_path);
 		ret = FALSE;
 		goto out;
 	}
diff --git a/src/up-device-kbd-backlight.c b/src/up-device-kbd-backlight.c
index b5944ab..658e95a 100644
--- a/src/up-device-kbd-backlight.c
+++ b/src/up-device-kbd-backlight.c
@@ -325,10 +325,11 @@ up_device_kbd_backlight_initable_init (GInitable     *initable,
 	if (klass->coldplug != NULL) {
 		ret = klass->coldplug (device);
 		if (!ret) {
-			g_debug ("failed to coldplug %s", native_path);
-			g_propagate_error (error, g_error_new (G_IO_ERROR, G_IO_ERROR_FAILED,
-			                                       "Failed to coldplug %s", native_path));
-
+			if (native_path) {
+				g_debug ("failed to coldplug %s", native_path);
+				g_propagate_error (error, g_error_new (G_IO_ERROR, G_IO_ERROR_FAILED,
+								       "Failed to coldplug %s", native_path));
+			}
 			return FALSE;
 		}
 	}