diff --git a/bin/markdown-tidy b/bin/markdown-tidy
index 727d5c1..21a9c60 100755
--- a/bin/markdown-tidy
+++ b/bin/markdown-tidy
@@ -100,9 +100,14 @@ def main(arguments: argparse.Namespace) -> None:
             outfile = open(
                 os.path.join(
                     arguments.outdir,
+                    # Black gets a little confused here and keeps
+                    # wrapping this conditional expression with
+                    # parentheses.
+                    # fmt: off
                     "stdin.md"
                     if infile.name == "<stdin>"
                     else os.path.basename(infile.name),
+                    # fmt: on
                 ),
                 "w",
             )
diff --git a/requirements.txt b/requirements.txt
index 5c8e7ea..9d1cf07 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,6 +2,6 @@
 # free and unencumbered software released into the public domain. For
 # more information, please refer to the accompanying "UNLICENCE" file.
 
-black==23.11.0
-flake8==6.1.0
-mypy==1.7.0
+black==24.3.0
+flake8==7.0.0
+mypy==1.9.0