diff --git a/units/05-bad-wtfos-system-list.sh b/units/05-bad-wtfos-system-list.sh
new file mode 100644
index 0000000..fbed151
--- /dev/null
+++ b/units/05-bad-wtfos-system-list.sh
@@ -0,0 +1,34 @@
+#/bin/sh
+
+#this script checks for a bad files list for the wtfos-system package
+#if it includes busybox we get into trouble when updating
+#and we can't fix this for existing installs with an update because of that
+
+#this health check cheats and autofixes the problem without user confirmation
+#if we don't they are liable to proceed to updating (which don't block on health checks)
+
+check () {
+    #if system.img is not mounted
+    if [ -f /opt/lib/opkg/info/wtfos-system.list ] && grep -q "busybox" /opt/lib/opkg/info/wtfos-system.list; then
+        fix
+    fi
+}
+
+fix () {
+    busybox sed -i '\/blackbox\/wtfos\/opt\/bin\/busybox/d' /opt/lib/opkg/info/wtfos-system.list
+}
+
+#run the check
+check
+result=$?
+if [ $result -ne 0 ]; then
+    #if the exit code wasn't zero
+    if [[ "$1" == "fix" ]]; then
+        #if the first arg is "fix" proceed to fix
+        fix
+        exit $?
+    else 
+        #otherwise exit with the check results
+        exit $result
+    fi
+fi