diff --git a/lslopt/lslparse.py b/lslopt/lslparse.py
index 057c4eb..4bf6124 100644
--- a/lslopt/lslparse.py
+++ b/lslopt/lslparse.py
@@ -1128,10 +1128,10 @@ list lazy_list_set(list L, integer i, list v)
                 if self.explicitcast:
                     if ltype == 'list' != rtype:
                         rexpr = {'nt':'CAST', 't':ltype, 'ch':[rexpr]}
-                        #rtype = ltype # unused
                     elif rtype == 'list' != ltype:
                         term = {'nt':'CAST', 't':rtype, 'ch':[term]}
-                        ltype = rtype
+                if rtype == 'list':
+                    ltype = rtype
                 term = {'nt':op, 't':ltype, 'ch':[term, rexpr]}
                 # Note that although list + nonlist is semantically the same as
                 # list + (list)nonlist and same goes for nonlist + list, they
diff --git a/testparser.py b/testparser.py
index 949cca9..a632b7f 100644
--- a/testparser.py
+++ b/testparser.py
@@ -270,7 +270,7 @@ class Test03_Optimizer(UnitTestCase):
                 integer j = 3||4&&5|6^7&8.==9!=10.e+01f<11<=12>13.>=14<<15>>16==0&&3==
                     ++f-f++-(3 + llFloor(f)<<3 << 32) - 2 - 0;
                 integer k = 2 + (3 * 25 - 4)/2 % 9;
-                a = (list)3; a += !3;
+                a = (list)3; a += !3; a = 3+a;
                 f += 4; f += -4.3;
                 integer i;
                 i = llGetListLength(L);