diff --git a/setup/git_post_checkout_hook.py b/setup/git_post_checkout_hook.py
index cc0fded419..04c5047a5b 100755
--- a/setup/git_post_checkout_hook.py
+++ b/setup/git_post_checkout_hook.py
@@ -19,7 +19,7 @@ def get_branch_name(rev):
 if flags == '1':  # A branch checkout
     prev_branch, cur_branch = list(map(get_branch_name, (prev_rev, current_rev)))
 
-    if 'qt6' in (prev_branch, cur_branch):
+    if {prev_branch, cur_branch} == {'master', 'qt6'}:
         os.rename('bypy/b/other-b', 'bypy/c')
         os.rename('bypy/b', 'bypy/c/other-b')
         os.rename('bypy/c', 'bypy/b')