diff --git a/src/_pytest/fixtures.py b/src/_pytest/fixtures.py
index 3a0ff1e3e01..d2e4e6d3313 100644
--- a/src/_pytest/fixtures.py
+++ b/src/_pytest/fixtures.py
@@ -963,7 +963,7 @@ def _dependee_fixture_argnames(self, request):
 
         stack_slice_index = min([current_fix_index, *parent_fixture_indexes])
         active_fixture_argnames = all_fix_names[:stack_slice_index]
-        return {*active_fixture_argnames, *self.argnames}
+        return tuple(active_fixture_argnames) + self.argnames
 
     def cache_key(self, request):
         return request.param_index if not hasattr(request, "param") else request.param