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
@@ -84,7 +84,7 @@
                         extra_arg, extra_arg_before, quiet, config):
   """Gets a command line for clang-tidy."""
   start = [clang_tidy_binary]
-  if allow_enabling_alpha_checkers is not None:
+  if allow_enabling_alpha_checkers:
     start.append('-allow-enabling-analyzer-alpha-checkers')
   if header_filter is not None:
     start.append('-header-filter=' + header_filter)