diff --git a/xarray/conventions.py b/xarray/conventions.py
index 6eff45c5b2d..e6fab022aa3 100644
--- a/xarray/conventions.py
+++ b/xarray/conventions.py
@@ -794,24 +794,4 @@ def cf_encoder(variables: T_Variables, attributes: T_Attrs):
 
     new_vars = {k: encode_cf_variable(v, name=k) for k, v in variables.items()}
 
-    # Remove attrs from bounds variables (issue #2921)
-    for var in new_vars.values():
-        bounds = var.attrs["bounds"] if "bounds" in var.attrs else None
-        if bounds and bounds in new_vars:
-            # see http://cfconventions.org/cf-conventions/cf-conventions.html#cell-boundaries
-            for attr in [
-                "units",
-                "standard_name",
-                "axis",
-                "positive",
-                "calendar",
-                "long_name",
-                "leap_month",
-                "leap_year",
-                "month_lengths",
-            ]:
-                if attr in new_vars[bounds].attrs and attr in var.attrs:
-                    if new_vars[bounds].attrs[attr] == var.attrs[attr]:
-                        new_vars[bounds].attrs.pop(attr)
-
     return new_vars, attributes
diff --git a/xarray/tests/test_coding_times.py b/xarray/tests/test_coding_times.py
index 9a5589ff872..c168993616f 100644
--- a/xarray/tests/test_coding_times.py
+++ b/xarray/tests/test_coding_times.py
@@ -732,23 +732,25 @@ def test_encode_time_bounds() -> None:
 
     encoded, _ = cf_encoder(ds.variables, ds.attrs)
     assert_equal(encoded["time_bounds"], expected["time_bounds"])
-    assert "calendar" not in encoded["time_bounds"].attrs
-    assert "units" not in encoded["time_bounds"].attrs
 
     # if time_bounds attrs are same as time attrs, it doesn't matter
     ds.time_bounds.encoding = {"calendar": "noleap", "units": "days since 2000-01-01"}
     encoded, _ = cf_encoder({k: v for k, v in ds.variables.items()}, ds.attrs)
     assert_equal(encoded["time_bounds"], expected["time_bounds"])
-    assert "calendar" not in encoded["time_bounds"].attrs
-    assert "units" not in encoded["time_bounds"].attrs
 
     # for CF-noncompliant case of time_bounds attrs being different from
     # time attrs; preserve them for faithful roundtrip
-    ds.time_bounds.encoding = {"calendar": "noleap", "units": "days since 1849-01-01"}
+    ds.time_bounds.encoding = {
+        "calendar": "gregorian",
+        "units": "days since 1849-01-01",
+    }
     encoded, _ = cf_encoder({k: v for k, v in ds.variables.items()}, ds.attrs)
     with pytest.raises(AssertionError):
         assert_equal(encoded["time_bounds"], expected["time_bounds"])
-    assert "calendar" not in encoded["time_bounds"].attrs
+    assert encoded["time"].attrs["calendar"] == ds.time.encoding["calendar"]
+    assert (
+        encoded["time_bounds"].attrs["calendar"] == ds.time_bounds.encoding["calendar"]
+    )
     assert encoded["time_bounds"].attrs["units"] == ds.time_bounds.encoding["units"]
 
     ds.time.encoding = {}