From 20ee6d25e42bf8e5ba5514c643e38c921f536d14 Mon Sep 17 00:00:00 2001
From: Richard Shadrach <45562402+rhshadrach@users.noreply.github.com>
Date: Fri, 18 Sep 2020 20:56:47 -0400
Subject: [PATCH] BUG: Concat typing (#36409)

---
 pandas/core/reshape/concat.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/pandas/core/reshape/concat.py b/pandas/core/reshape/concat.py
index dd4bcf77641ef..a07c7b49ac55b 100644
--- a/pandas/core/reshape/concat.py
+++ b/pandas/core/reshape/concat.py
@@ -31,6 +31,7 @@
 
 if TYPE_CHECKING:
     from pandas import DataFrame
+    from pandas.core.generic import NDFrame
 
 # ---------------------------------------------------------------------
 # Concatenate DataFrame objects
@@ -54,7 +55,7 @@ def concat(
 
 @overload
 def concat(
-    objs: Union[Iterable[FrameOrSeries], Mapping[Label, FrameOrSeries]],
+    objs: Union[Iterable["NDFrame"], Mapping[Label, "NDFrame"]],
     axis=0,
     join: str = "outer",
     ignore_index: bool = False,
@@ -69,7 +70,7 @@ def concat(
 
 
 def concat(
-    objs: Union[Iterable[FrameOrSeries], Mapping[Label, FrameOrSeries]],
+    objs: Union[Iterable["NDFrame"], Mapping[Label, "NDFrame"]],
     axis=0,
     join="outer",
     ignore_index: bool = False,