diff --git a/include/tests_insecure_services b/include/tests_insecure_services
index c958d432..df616e56 100644
--- a/include/tests_insecure_services
+++ b/include/tests_insecure_services
@@ -476,7 +476,7 @@
         FOUND=""
         PACKAGES="atftpd tftpd tftp-server tftpd-hpa"
         for PACKAGE in ${PACKAGES}; do
-            if PackageIsInstalled ${PACKAGE}; then
+            if PackageIsInstalled "${PACKAGE}"; then
                 FOUND="${PACKAGE}"
             fi
         done