diff --git a/econml/_cate_estimator.py b/econml/_cate_estimator.py
index 3c453b291..c1f9e26d8 100644
--- a/econml/_cate_estimator.py
+++ b/econml/_cate_estimator.py
@@ -599,7 +599,6 @@ def effect(self, X=None, *, T0, T1):
         # of rows of T was not taken into account
         if X is None:
             eff = np.repeat(eff, shape(T0)[0], axis=0)
-        m = shape(eff)[0]
         dT = T1 - T0
         einsum_str = 'myt,mt->my'
         if ndim(dT) == 1:
@@ -852,7 +851,7 @@ def _expand_treatments(self, X=None, *Ts, transform=True):
         n_rows = 1 if X is None else shape(X)[0]
         outTs = []
         for T in Ts:
-            if (ndim(T) == 0) and self._d_t_in and self._d_t_in[0] > 1:
+            if (ndim(T) == 0) and self._d_t_in and self._d_t_in[0] > 1 and T != 0:
                 warn("A scalar was specified but there are multiple treatments; "
                      "the same value will be used for each treatment.  Consider specifying"
                      "all treatments, or using the const_marginal_effect method.")