diff --git a/testfuncs.py b/testfuncs.py
index 50b57d8..2eb1a89 100644
--- a/testfuncs.py
+++ b/testfuncs.py
@@ -535,7 +535,7 @@ def do_tests():
     shouldexcept('div(NaN, 1)', ELSLMathError)
     shouldexcept('div(1, NaN)', ELSLMathError)
     shouldexcept('div(F32(1e40), F32(1e40))', ELSLMathError)
-    shouldexcept('zstr("blah")', ELSLInvalidType)
+    shouldexcept('zstr(b"blah")', ELSLInvalidType)
     test('div(1, 9)', 0)
     test('div(8, 9)', 0)
     test('div(9, 9)', 1)
@@ -619,8 +619,8 @@ def do_tests():
     shouldexcept('mul(1.,Quaternion((1.,2.,3.,4.)))', ELSLTypeMismatch)
     shouldexcept('mul(Quaternion((1.,2.,3.,4.)),1.)', ELSLTypeMismatch)
     shouldexcept('mul(Quaternion((1.,2.,3.,4.)),Vector((1.,2.,3.)))', ELSLTypeMismatch)
-    shouldexcept('mul("a",3)', ELSLInvalidType)
-    shouldexcept('mul(Vector((3.,4.,5.)),"a")', ELSLInvalidType)
+    shouldexcept('mul(b"a",3)', ELSLInvalidType)
+    shouldexcept('mul(Vector((3.,4.,5.)),b"a")', ELSLInvalidType)
     shouldexcept('typecast([1,F32(3.14),Key(u"blah"),Quaternion((1.,0.,0.,0.))], Vector)',
         ELSLTypeMismatch)
     shouldexcept('typecast(b"", unicode)', ELSLInvalidType)