diff --git a/lib/tempest b/lib/tempest
index 4a192a0..96c9ced 100644
--- a/lib/tempest
+++ b/lib/tempest
@@ -130,6 +130,8 @@
     local available_flavors
     local flavors_ref
     local flavor_lines
+    local flavor_ref_size
+    local flavor_ref_alt_size
     local public_network_id
     local public_router_id
     local ssh_connect_method="floating"
@@ -233,11 +235,24 @@
             fi
             flavor_ref=${flavors[0]}
             flavor_ref_alt=$flavor_ref
+            flavor_ref_size=$(openstack flavor show --format value --column disk "${flavor_ref}")
 
             # 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" != "$flavor_ref" ]]; then
+                    #
+                    # NOTE(sdatko): Resize is only possible when target flavor
+                    #               is not smaller than the original one. For
+                    #               Tempest tests, in case there was a bigger
+                    #               flavor selected as default, e.g. m1.small,
+                    #               we need to perform additional check.
+                    #
+                    flavor_ref_alt_size=$(openstack flavor show --format value --column disk "${f}")
+                    if [[ "${flavor_ref_alt_size}" -lt "${flavor_ref_size}" ]]; then
+                        continue
+                    fi
+
                     flavor_ref_alt=$f
                     break
                 fi