diff --git a/modin/backends/base/query_compiler.py b/modin/backends/base/query_compiler.py
index 980f7ac2467..06b74d43e3a 100644
--- a/modin/backends/base/query_compiler.py
+++ b/modin/backends/base/query_compiler.py
@@ -1412,8 +1412,6 @@ def groupby_agg(
                 by = by.columns[0] if drop else by.to_pandas().squeeze()
             elif isinstance(by, type(self)):
                 by = list(by.columns)
-            else:
-                by = by
         else:
             by = by.to_pandas().squeeze() if isinstance(by, type(self)) else by