diff --git a/sphinx/websupport/search/__init__.py b/sphinx/websupport/search/__init__.py
index 385c3fa97..10e3532d3 100644
--- a/sphinx/websupport/search/__init__.py
+++ b/sphinx/websupport/search/__init__.py
@@ -102,7 +102,7 @@ class BaseSearch(object):
         res = self.context_re.search(text)
         if res is None:
             return ''
-        context_start = max(res.start() - length/2, 0)
+        context_start = max(res.start() - int(length/2), 0)
         context_end = context_start + length
         context = ''.join([context_start > 0 and '...' or '',
                            text[context_start:context_end],
diff --git a/tox.ini b/tox.ini
index a64a24041..b6dedfc01 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,6 +4,8 @@ envlist=py25,py26,py27,py31,py32,py33,pypy,du09,du08,du07
 [testenv]
 deps=
     nose
+    sqlalchemy
+    whoosh
 setenv =
     BUILD_TEST_PATH = {envdir}/tests
 commands=