diff --git a/pymc/distributions/transforms.py b/pymc/distributions/transforms.py
index bdb63285c9d..b3c23b7e008 100644
--- a/pymc/distributions/transforms.py
+++ b/pymc/distributions/transforms.py
@@ -61,6 +61,10 @@ def __getattr__(name):
         warnings.warn(f"{name} has been deprecated, use sum_to_1 instead.", FutureWarning)
         return sum_to_1
 
+    if name == "sum_to_1":
+        warnings.warn("sum_to_1 has been deprecated, use simplex instead.", FutureWarning)
+        return simplex
+
     if name == "RVTransform":
         warnings.warn("RVTransform has been renamed to Transform", FutureWarning)
         return Transform
@@ -334,6 +338,7 @@ def log_jac_det(self, value, *rv_inputs):
 Instantiation of :class:`pymc.logprob.transforms.LogTransform`
 for use in the ``transform`` argument of a random variable."""
 
+# Deprecated
 sum_to_1 = SumTo1()
 sum_to_1.__doc__ = """
 Instantiation of :class:`pymc.distributions.transforms.SumTo1`
diff --git a/tests/distributions/test_transform.py b/tests/distributions/test_transform.py
index 8196c2623cf..3bf0c8baf1f 100644
--- a/tests/distributions/test_transform.py
+++ b/tests/distributions/test_transform.py
@@ -675,3 +675,6 @@ def test_deprecated_ndim_supp_transforms():
 
     with pytest.warns(FutureWarning, match="deprecated"):
         assert tr.multivariate_sum_to_1 == tr.sum_to_1
+
+    with pytest.warns(FutureWarning, match="deprecated"):
+        assert tr.sum_to_1 == tr.simplex