diff --git a/tools/Python/mctest/mcviewtest.py b/tools/Python/mctest/mcviewtest.py
index bfa53d3aa1..d5ebc55716 100644
--- a/tools/Python/mctest/mcviewtest.py
+++ b/tools/Python/mctest/mcviewtest.py
@@ -6,7 +6,7 @@
 import math
 import sys
 import os
-from os.path import join, dirname, isdir
+from os.path import join, dirname
 from os import walk
 import shutil
 import concurrent.futures
@@ -54,19 +54,14 @@ def ok(v, e):
     return insigma if targeterr is not None else (within20 or insigma)
 
 def scantree(path):
-    """Recursively yield DirEntry objects for given directory."""
+    """Yield DirEntry objects for complete test label dirs, i.e. holding testresults_<label>.json."""
     for entry in os.scandir(path):
-        if entry.is_dir(follow_symlinks=True):
+        if entry.is_dir() and os.path.isfile(join(entry.path, "testresults_%s.json" % entry.name)):
             yield entry
 
 def get_oldest_dir(directory_name):
-    files = []
-
-    for file in scantree(directory_name):
-        files.append((file.stat().st_mtime, file.path))
-
-    files.sort(key=lambda x:x[0])
-    return files[0][1]
+    files = [(e.stat().st_mtime, e.path) for e in scantree(directory_name)]
+    return min(files)[1] if files else None
 
 def get_default_diffworkers():
     ''' Number of mcplotdiff-html comparisons to run in parallel by default:
@@ -403,16 +398,7 @@ def iterate_obj_to_populate_rows(iterobj, otherobjs, rows, ncols, use_iterobj_re
                     row.append(get_empty_cell_tuple("not on branch"))
 
     # load test data
-    alllabels = list()
-    for root, labels, files in walk(testdir):
-        for lab in labels:
-            if isdir(lab):
-                try:
-                    obj = json.loads(open(join(testdir, lab, "testresults_%s.json" % lab)).read())
-                    alllabels.append(lab)
-                except:
-                    pass
-    alllabels.sort()
+    alllabels = sorted(e.name for e in scantree(testdir))
     # get number of data columns
     numcols= len(alllabels)