diff --git a/include/tests_ports_packages b/include/tests_ports_packages
index 0a4b77bc..1c196629 100644
--- a/include/tests_ports_packages
+++ b/include/tests_ports_packages
@@ -1349,7 +1349,7 @@
                     fi
                 done
 
-                if [ $UNATTENDED_UPGRADES_OPTION_AVAILABLE -eq 1 ]; then
+                if [ ${UNATTENDED_UPGRADES_OPTION_AVAILABLE} -eq 1 ]; then
                     # Test available tools for Linux
                     if [ -f "${ROOTDIR}bin/auter" ]; then
                         UNATTENDED_UPGRADES_TOOL="auter"