diff --git a/sumpy/expansion/__init__.py b/sumpy/expansion/__init__.py
index d3dfbccb1de7edfd262f7daa5eb920b24ca937da..17264e8e791b974529578e5de10719aaa71698ea 100644
--- a/sumpy/expansion/__init__.py
+++ b/sumpy/expansion/__init__.py
@@ -196,7 +196,8 @@ class ExpansionTermsWrangler(object):
         if self.max_mi is None:
             return res
 
-        return [mi for mi in res if all(mi[i] <= self.max_mi[i])]
+        return [mi for mi in res if
+            all(mi[i] <= self.max_mi[i] for i in range(self.dim))]
 
     def copy(self, **kwargs):
         new_kwargs = dict(
diff --git a/sumpy/expansion/local.py b/sumpy/expansion/local.py
index 6080f646d29afdcb318e97e318a567f5389e42f8..3acdfea0d6c954d0db8cc937be5211ab53edd53e 100644
--- a/sumpy/expansion/local.py
+++ b/sumpy/expansion/local.py
@@ -240,6 +240,10 @@ class VolumeTaylorLocalExpansionBase(LocalExpansionBase):
 
             from sumpy.tools import add_mi
 
+            # Calculate a elementwise maximum multi-index because the number
+            # of multi-indices needed is much less than
+            # gnitstam(src_order + tgt order) when PDE conforming expansions
+            # are used. For full Taylor, there's no difference.
             max_mi = [0]*self.dim
             for i in range(self.dim):
                 max_mi[i] = max(mi[i] for mi in