diff --git a/colcon_test_result/verb/test_result.py b/colcon_test_result/verb/test_result.py
index 9765445..3563062 100644
--- a/colcon_test_result/verb/test_result.py
+++ b/colcon_test_result/verb/test_result.py
@@ -1,7 +1,6 @@
 # Copyright 2016-2019 Dirk Thomas
 # Licensed under the Apache License, Version 2.0
 
-import argparse
 from contextlib import suppress
 import os
 import sys
@@ -27,7 +26,6 @@ def __init__(self):  # noqa: D107
     def add_arguments(self, *, parser):  # noqa: D102
         parser.add_argument(
             '--test-result-base',
-            type=_argparse_existing_dir,
             default='build',
             help='The base path for all test results (default: build)')
         parser.add_argument(
@@ -55,6 +53,8 @@ def add_arguments(self, *, parser):  # noqa: D102
             help='Same as --delete without an interactive confirmation')
 
     def main(self, *, context):  # noqa: D102
+        _verify_dir_exists(context.args.test_result_base)
+
         all_files = set() \
             if (context.args.delete or context.args.delete_yes) else None
         all_results = list(get_test_results(
@@ -109,11 +109,11 @@ def main(self, *, context):  # noqa: D102
         return 1 if summary.error_count or summary.failure_count else 0
 
 
-def _argparse_existing_dir(path):
+def _verify_dir_exists(path):
     if not os.path.exists(path):
-        raise argparse.ArgumentTypeError("Path '%s' does not exist" % path)
+        raise RuntimeError("Path '%s' does not exist" % path)
     if not os.path.isdir(path):
-        raise argparse.ArgumentTypeError("Path '%s' is not a directory" % path)
+        raise RuntimeError("Path '%s' is not a directory" % path)
     return path
 
 
diff --git a/test/spell_check.words b/test/spell_check.words
index 0748c53..d2a32f2 100644
--- a/test/spell_check.words
+++ b/test/spell_check.words
@@ -1,5 +1,4 @@
 apache
-argparse
 basepath
 classname
 colcon