diff --git a/betterproto/tests/generate.py b/betterproto/tests/generate.py
index 03a5c2a..c33f30b 100644
--- a/betterproto/tests/generate.py
+++ b/betterproto/tests/generate.py
@@ -1,30 +1,62 @@
 #!/usr/bin/env python
 import os
+import sys
+from typing import Set
+
+from betterproto.tests.util import get_directories, inputs_path, output_path_betterproto, output_path_reference, \
+    protoc_plugin, protoc_reference
 
 # Force pure-python implementation instead of C++, otherwise imports
 # break things because we can't properly reset the symbol database.
 os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
 
 
-from betterproto.tests.util import get_directories, protoc_plugin, protoc_reference, root_path
+def generate(whitelist: Set[str]):
+    path_whitelist = {os.path.realpath(e) for e in whitelist if os.path.exists(e)}
+    name_whitelist = {e for e in whitelist if not os.path.exists(e)}
 
-def main():
-    os.chdir(root_path)
-    test_cases_directory = os.path.join(root_path, 'inputs')
-    test_case = get_directories(test_cases_directory)
+    test_case_names = set(get_directories(inputs_path))
 
-    for test_case_name in test_case:
-        test_case_path = os.path.join(test_cases_directory, test_case_name)
+    for test_case_name in test_case_names:
+        test_case_path = os.path.join(inputs_path, test_case_name)
 
-        case_reference_output_dir = os.path.join(root_path, 'output_reference', test_case_name)
-        case_plugin_output_dir = os.path.join(root_path, 'output_betterproto', test_case_name)
+        is_path_whitelisted = path_whitelist and os.path.realpath(test_case_path) in path_whitelist
+        is_name_whitelisted = name_whitelist and test_case_name in name_whitelist
+
+        if whitelist and not is_path_whitelisted and not is_name_whitelisted:
+            continue
+
+        case_output_dir_reference = os.path.join(output_path_reference, test_case_name)
+        case_output_dir_betterproto = os.path.join(output_path_betterproto, test_case_name)
 
         print(f'Generating output for {test_case_name}')
-        os.makedirs(case_reference_output_dir, exist_ok=True)
-        os.makedirs(case_plugin_output_dir, exist_ok=True)
+        os.makedirs(case_output_dir_reference, exist_ok=True)
+        os.makedirs(case_output_dir_betterproto, exist_ok=True)
 
-        protoc_reference(test_case_path, case_reference_output_dir)
-        protoc_plugin(test_case_path, case_plugin_output_dir)
+        protoc_reference(test_case_path, case_output_dir_reference)
+        protoc_plugin(test_case_path, case_output_dir_betterproto)
+
+
+HELP = "\n".join([
+    'Usage: python generate.py',
+    '       python generate.py [DIRECTORIES or NAMES]',
+    'Generate python classes for standard tests.',
+    '',
+    'DIRECTORIES    One or more relative or absolute directories of test-cases to generate classes for.',
+    '               python generate.py inputs/bool inputs/double inputs/enum',
+    '',
+    'NAMES          One or more test-case names to generate classes for.',
+    '               python generate.py bool double enums'
+])
+
+
+def main():
+    if sys.argv[1] in ('-h', '--help'):
+        print(HELP)
+        return
+    whitelist = set(sys.argv[1:])
+
+    generate(whitelist)
 
 
 if __name__ == "__main__":
diff --git a/betterproto/tests/util.py b/betterproto/tests/util.py
index c65e2a6..b627a23 100644
--- a/betterproto/tests/util.py
+++ b/betterproto/tests/util.py
@@ -6,6 +6,8 @@ os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
 
 root_path = os.path.dirname(os.path.realpath(__file__))
 inputs_path = os.path.join(root_path, 'inputs')
+output_path_reference = os.path.join(root_path, 'output_reference')
+output_path_betterproto = os.path.join(root_path, 'output_betterproto')
 
 if os.name == 'nt':
     plugin_path = os.path.join(root_path, '..', 'plugin.bat')