diff --git a/lib/mpl_toolkits/axes_grid1/axes_grid.py b/lib/mpl_toolkits/axes_grid1/axes_grid.py
index 2a2e0778e2e2..ea47ecaa54d5 100644
--- a/lib/mpl_toolkits/axes_grid1/axes_grid.py
+++ b/lib/mpl_toolkits/axes_grid1/axes_grid.py
@@ -271,7 +271,6 @@ def set_label_mode(self, mode):
             - "1": Only the bottom left axes is labelled.
             - "all": all axes are labelled.
         """
-        _api.check_in_list(["all", "L", "1"], mode=mode)
         if mode == "all":
             for ax in self.axes_all:
                 _tick_only(ax, False, False)
@@ -292,7 +291,7 @@ def set_label_mode(self, mode):
                 ax = col[-1]
                 _tick_only(ax, bottom_on=False, left_on=True)
 
-        else:  # "1"
+        elif mode == "1":
             for ax in self.axes_all:
                 _tick_only(ax, bottom_on=True, left_on=True)