diff --git a/bin/bump_version.py b/bin/bump_version.py
index 60b8ce5b..3f47630b 100755
--- a/bin/bump_version.py
+++ b/bin/bump_version.py
@@ -18,7 +18,7 @@ import cibuildwheel
 config = [
     # file path, version find/replace format
     ("README.md", "cibuildwheel=={}"),
-    ("cibuildwheel/__init__.py", "__version__ = '{}'"),
+    ("cibuildwheel/__init__.py", '__version__ = "{}"'),
     ("docs/faq.md", "cibuildwheel=={}"),
     ("docs/faq.md", "cibuildwheel@v{}"),
     ("docs/setup.md", "cibuildwheel=={}"),