diff --git a/pandas/tests/indexes/test_multi.py b/pandas/tests/indexes/test_multi.py
index bec52f5f47b09..fb5576bed90b4 100644
--- a/pandas/tests/indexes/test_multi.py
+++ b/pandas/tests/indexes/test_multi.py
@@ -6,7 +6,7 @@
 import re
 import warnings
 
-from pandas import (date_range, MultiIndex, Index, CategoricalIndex,
+from pandas import (DataFrame, date_range, MultiIndex, Index, CategoricalIndex,
                     compat)
 from pandas.core.common import PerformanceWarning
 from pandas.indexes.base import InvalidIndexError
@@ -2201,6 +2201,15 @@ def test_partial_string_timestamp_multiindex(self):
         with assertRaises(KeyError):
             df_swap.loc['2016-01-01']
 
+        # GH12685 (partial string with daily resolution or below)
+        dr = date_range('2013-01-01', periods=100, freq='D')
+        ix = MultiIndex.from_product([dr, ['a', 'b']])
+        df = DataFrame(np.random.randn(200, 1), columns=['A'], index=ix)
+
+        result = df.loc[idx['2013-03':'2013-03', :], :]
+        expected = df.iloc[118:180]
+        tm.assert_frame_equal(result, expected)
+
     def test_rangeindex_fallback_coercion_bug(self):
         # GH 12893
         foo = pd.DataFrame(np.arange(100).reshape((10, 10)))