diff --git a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
--- a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
+++ b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
@@ -225,7 +225,8 @@
   parser.add_argument('-checks', default=None,
                       help='checks filter, when not specified, use clang-tidy '
                       'default')
-  parser.add_argument('-config', default=None,
+  group = parser.add_mutually_exclusive_group()
+  group.add_argument('-config', default=None,
                       help='Specifies a configuration in YAML/JSON format: '
                       '  -config="{Checks: \'*\', '
                       '                       CheckOptions: [{key: x, '
@@ -233,9 +234,9 @@
                       'When the value is empty, clang-tidy will '
                       'attempt to find a file named .clang-tidy for '
                       'each source file in its parent directories.')
-  parser.add_argument('-config-file', default=None,
+  group.add_argument('-config-file', default=None,
                       help='Specify the path of .clang-tidy or custom config'
-                      'file: e.g. -config-file=/some/path/myTidyConfigFile'
+                      ' file: e.g. -config-file=/some/path/myTidyConfigFile'
                       'This option internally works exactly the same way as'
                       '-config option after reading specified config file.'
                       'Use either -config-file or -config, not both.')