diff --git a/tests/test-utils.py b/tests/test-utils.py
new file mode 100644
index 0000000..45e3cdd
--- /dev/null
+++ b/tests/test-utils.py
@@ -0,0 +1,11 @@
+import nose.tools
+
+from twill import utils
+from twill.errors import TwillException
+
+
+class TestMakeBoolean:
+
+    @nose.tools.raises(TwillException)
+    def test_twill_exception(self):
+        utils.make_boolean('no')
diff --git a/twill/utils.py b/twill/utils.py
index fd305de..b1f78d8 100644
--- a/twill/utils.py
+++ b/twill/utils.py
@@ -15,6 +15,8 @@
 from mechanize._util import time
 from mechanize._http import HTTPRefreshProcessor
 from mechanize import BrowserStateError
+from twill.errors import TwillException
+
 
 class ResultWrapper:
     """