diff --git a/clang/docs/tools/dump_format_style.py b/clang/docs/tools/dump_format_style.py
index c82b4479f299d9..c98f2bdcb4f2f0 100755
--- a/clang/docs/tools/dump_format_style.py
+++ b/clang/docs/tools/dump_format_style.py
@@ -20,7 +20,7 @@
 PLURALS_FILE = os.path.join(os.path.dirname(__file__), "plurals.txt")
 
 plurals: Set[str] = set()
-with open(PLURALS_FILE, "a+") as f:
+with open(PLURALS_FILE) as f:
     f.seek(0)
     plurals = set(f.read().splitlines())