diff --git a/sdks/python/apache_beam/dataframe/frames.py b/sdks/python/apache_beam/dataframe/frames.py
index e2390bda28be..a0a99c12ecdd 100644
--- a/sdks/python/apache_beam/dataframe/frames.py
+++ b/sdks/python/apache_beam/dataframe/frames.py
@@ -1471,8 +1471,10 @@ def compute_idx(s):
     index = pd.Index([], dtype=index_dtype)
     proxy = self._expr.proxy().copy()
     proxy.index = index
-    proxy = proxy.append(
-        pd.Series([1], index=np.asarray(['0']).astype(proxy.index.dtype)))
+    proxy = pd.concat([
+        proxy,
+        pd.Series([1], index=np.asarray(['0']).astype(proxy.index.dtype))
+    ])
 
     idx_func = expressions.ComputedExpression(
         'idx_func',