diff --git a/config/rootfiles/core/163/update.sh b/config/rootfiles/core/163/update.sh
index e51dbf0b3..c1f23f25e 100644
--- a/config/rootfiles/core/163/update.sh
+++ b/config/rootfiles/core/163/update.sh
@@ -24,6 +24,9 @@
 . /opt/pakfire/lib/functions.sh
 /usr/local/bin/backupctrl exclude >/dev/null 2>&1
 
+# Abort in case of uninitialised variables
+set -u
+
 core=163
 
 exit_with_error() {