diff --git a/lslopt/lslbasefuncs.py b/lslopt/lslbasefuncs.py
index cdd0cb2..4de1cd0 100644
--- a/lslopt/lslbasefuncs.py
+++ b/lslopt/lslbasefuncs.py
@@ -552,7 +552,7 @@ def InternalTypecast(val, out, InList, f32):
         if out in (Vector, Quaternion):
             Z,dim = (ZERO_VECTOR,3) if out == Vector else (ZERO_ROTATION,4)
             ret = []
-            if val[0:1] != u'<':
+            if not val.startswith(u'<'):
                 return Z
             val = val[1:]
             for _ in range(dim):
@@ -562,7 +562,8 @@ def InternalTypecast(val, out, InList, f32):
                 if match.group(1):
                     ret.append(F32(float.fromhex(match.group(0)), f32))
                 elif match.group(2):
-                    ret.append(Indet if match.group(0)[0] == '-' else NaN)
+                    ret.append(Indet if match.group(0).startswith(u'-') else
+                        NaN)
                 else:
                     ret.append(F32(float(match.group(0)), f32))
                 if len(ret) < dim:
diff --git a/lslopt/lslloadlib.py b/lslopt/lslloadlib.py
index f924234..1b136ce 100644
--- a/lslopt/lslloadlib.py
+++ b/lslopt/lslloadlib.py
@@ -175,7 +175,8 @@ def LoadLibrary(builtins = None, fndata = None):
                     value = None
                 elif typ in (u'vector', u'rotation'):
                     try:
-                        if value[0:1] != u'<' or value[-1:] != u'>':
+                        if not (value.startswith(u'<') and value.endswith(u'>')
+                                ):
                             raise ValueError
                         value = value[1:-1].split(u',')
                         if len(value) != (3 if typ == 'vector' else 4):
@@ -205,7 +206,8 @@ def LoadLibrary(builtins = None, fndata = None):
                                 u" line %d: %s" % (ubuiltins, linenum, line))
                 else:
                     assert typ == u'list'
-                    if value[0:1] != u'[' or value[-1:] != u']':
+                    if not (value.startswith(u'[') and value.endswith(u']')
+                            ):
                         warning(u"Invalid list value in %s, line %d: %s"
                                 % (ubuiltins, linenum, line))
                     elif value[1:-1].strip() != '':