diff --git a/pandas/tests/indexing/multiindex/test_loc.py b/pandas/tests/indexing/multiindex/test_loc.py
index 104fa2da7a67e..aef9fdec5d593 100644
--- a/pandas/tests/indexing/multiindex/test_loc.py
+++ b/pandas/tests/indexing/multiindex/test_loc.py
@@ -912,3 +912,13 @@ def test_loc_keyerror_rightmost_key_missing():
     df = df.set_index(["A", "B"])
     with pytest.raises(KeyError, match="^1$"):
         df.loc[(100, 1)]
+def test_loc_multiindex():
+    #43599
+    df = DataFrame(
+        index = MultiIndex.from_product([list("abc"), list("de"), list("f")]), columns = ["Val"]
+        )
+    result = df.loc[np.s_[:,"d",:]]
+    expected = DataFrame(
+        index = MultiIndex.from_product([list("abc"), list("d"), list("f")]), columns = ["Val"]
+        )
+    tm.assert_frame_equal(result, expected)
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index 25c0625d1d790..64ee6acfeb901 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -40,6 +40,7 @@
 from pandas.tests.indexing.common import Base
 
 
+
 class TestLoc(Base):
     def test_loc_getitem_int(self):