diff --git a/python/hpackcheck.py b/python/hpackcheck.py
index 09fb71c8..070f382c 100755
--- a/python/hpackcheck.py
+++ b/python/hpackcheck.py
@@ -30,7 +30,12 @@ def testsuite(testdata):
         hdrs.sort()
         expected_hdrs.sort()
         if hdrs != expected_hdrs:
-            sys.stderr.write('FAIL case#{}\n'.format(casenum + 1))
+            if 'seqno' in item:
+                seqno = item['seqno']
+            else:
+                seqno = casenum
+
+            sys.stderr.write('FAIL seqno#{}\n'.format(seqno))
             sys.stderr.write('expected:\n')
             for k, v in expected_hdrs:
                 sys.stderr.write('{}: {}\n'.format(k, v))
diff --git a/python/hpackmake.py b/python/hpackmake.py
index c990e4bf..32de2f67 100755
--- a/python/hpackmake.py
+++ b/python/hpackmake.py
@@ -28,6 +28,7 @@ result in less bits on the wire.'''
     deflater.change_table_size(table_size)
     for casenum, item  in enumerate(testdata['cases']):
         outitem = {
+            'seqno': casenum,
             'headers': item['headers']
         }
         casenum += 1