diff --git a/modules/battery.c b/modules/battery.c
index 20eaad0..d394f94 100644
--- a/modules/battery.c
+++ b/modules/battery.c
@@ -348,7 +348,7 @@ run(struct module *mod)
             struct udev_device *dev = udev_monitor_receive_device(mon);
             const char *sysname = udev_device_get_sysname(dev);
 
-            bool is_us = strcmp(sysname, m->battery) == 0;
+            bool is_us = sysname != NULL && strcmp(sysname, m->battery) == 0;
             udev_device_unref(dev);
 
             if (!is_us)