diff --git a/sphinx/cmd/build.py b/sphinx/cmd/build.py
index 263794a5a..cf50f1730 100644
--- a/sphinx/cmd/build.py
+++ b/sphinx/cmd/build.py
@@ -9,9 +9,11 @@
 """
 
 import argparse
+import bdb
 import locale
 import multiprocessing
 import os
+import pdb
 import sys
 import traceback
 from typing import Any, IO, List
@@ -29,13 +31,10 @@ from sphinx.util.docutils import docutils_namespace, patch_docutils
 
 
 def handle_exception(app: Sphinx, args: Any, exception: BaseException, stderr: IO = sys.stderr) -> None:  # NOQA
-    import bdb
-
     if isinstance(exception, bdb.BdbQuit):
         return
 
     if args.pdb:
-        import pdb
         print(red(__('Exception occurred while building, starting debugger:')),
               file=stderr)
         traceback.print_exc()