diff --git a/lib/tempest b/lib/tempest
index a9461d4..cf7eb6f 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -223,7 +223,7 @@
             # Ensure ``flavor_ref`` and ``flavor_ref_alt`` have different values.
             # Some resize instance in tempest tests depends on this.
             for f in ${flavors[@]:1}; do
-                if [[ $f -ne $flavor_ref ]]; then
+                if [[ "$f" != "$flavor_ref" ]]; then
                     flavor_ref_alt=$f
                     break
                 fi