diff --git a/tempest/common/custom_matchers.py b/tempest/common/custom_matchers.py
index 307d5db..81b5153 100644
--- a/tempest/common/custom_matchers.py
+++ b/tempest/common/custom_matchers.py
@@ -125,7 +125,7 @@
             elif key == 'content-type' and not value:
                 return InvalidFormat(key, value)
             elif key == 'x-trans-id' and \
-                not re.match("^tx[0-9a-f]*-[0-9a-f]*$", value):
+                not re.match("^tx[0-9a-f]{21}-[0-9a-f]{10}.*", value):
                 return InvalidFormat(key, value)
             elif key == 'date' and not value:
                 return InvalidFormat(key, value)