diff --git a/test/test_results.py b/test/test_results.py
index 944f14d9..37dea38c 100644
--- a/test/test_results.py
+++ b/test/test_results.py
@@ -353,28 +353,23 @@ def generate_tests():
 
     # enable selective testing for direct calls
     if __name__ == '__main__' and len(sys.argv) > 1:
-        if sys.argv[1].lower() == "all":
-            fltr = lambda c, bc: True  # noqa: E731
-        elif sys.argv[1].lower() == "broken":
-            fltr = lambda c, bc: c in BROKEN  # noqa: E731
-        else:
-            argv = sys.argv[1:]
-            fltr = lambda c, bc: c in argv or bc in argv  # noqa: E731
+        categories = sys.argv[1:]
+        negate = False
+        if categories[0].lower() == "all":
+            categories = ()
+            negate = True
+        elif categories[0].lower() == "broken":
+            categories = BROKEN
         del sys.argv[1:]
     else:
-        skip = set(BROKEN)
-        if skip:
-            print("skipping:", ", ".join(skip))
-        fltr = lambda c, bc: c not in skip  # noqa: E731
-
-    # filter available extractor classes
-    extractors = [
-        extr for extr in extractor.extractors()
-        if fltr(extr.category, extr.basecategory)
-    ]
+        categories = BROKEN
+        negate = True
+        if categories:
+            print("skipping:", ", ".join(categories))
+    fltr = util.build_extractor_filter(categories, negate=negate)
 
     # add 'test_...' methods
-    for extr in extractors:
+    for extr in filter(fltr, extractor.extractors()):
         name = "test_" + extr.__name__ + "_"
         for num, tcase in enumerate(extr._get_tests(), 1):
             test = _generate_test(extr, tcase)