diff --git a/.travis.yml b/.travis.yml
index 3b846e5..53b1684 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,27 +1,25 @@
 language: python
 
 python:
-    - "2.7"
-    - "3.4"
+- "2.7"
 
 env:
-    - TOXENV=py27-d15
-    - TOXENV=py27-d16
-    - TOXENV=py27-d17
-    - TOXENV=py33-d17
-    - TOXENV=cov
+- TOXENV=py27-d16
+- TOXENV=py27-d17
+- TOXENV=py34-d17
+- TOXENV=cov
 
 branches:
     only:
-        - master
-        - develop
+    - master
+    - develop
 
 install: pip install --quiet --use-mirrors tox
 
 script: tox
 
 after_script:
-    - if [ $TOXENV == "cov" ]; then
-        pip install --quiet --use-mirrors coveralls;
-        coveralls;
-      fi
+- if [ $TOXENV == "cov" ]; then
+    pip install --quiet --use-mirrors coveralls;
+    coveralls;
+  fi
diff --git a/README.rst b/README.rst
index 60d7c66..69afb7a 100644
--- a/README.rst
+++ b/README.rst
@@ -40,7 +40,7 @@ Requirements
 ============
 
 - python >= 2.7
-- django >= 1.5
+- django >= 1.6
 - markdown
 
 
diff --git a/django_markdown/templatetags/django_markdown_static.py b/django_markdown/templatetags/django_markdown_static.py
index b767dc7..8ef6876 100644
--- a/django_markdown/templatetags/django_markdown_static.py
+++ b/django_markdown/templatetags/django_markdown_static.py
@@ -1,17 +1,14 @@
-from django.apps import apps
+from django.conf import settings
 from django.template import Library
 
 register = Library()
 
-_static = None
+if 'django.contrib.staticfiles' in settings.INSTALLED_APPS:
+    from django.contrib.staticfiles.templatetags.staticfiles import static as _static
+else:
+    from django.templatetags.static import static as _static
 
 
 @register.simple_tag
 def static(path):
-    global _static
-    if _static is None:
-        if apps.is_installed('django.contrib.staticfiles'):
-            from django.contrib.staticfiles.templatetags.staticfiles import static as _static
-        else:
-            from django.templatetags.static import static as _static
     return _static(path)
diff --git a/tox.ini b/tox.ini
index d0fc436..b0df3bd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist=py27-d15,py27-d16,py27-d17,py33-d17,cov
+envlist=py27-d16,py27-d17,py34-d17,cov
 
 [pylama]
 skip=example/*
@@ -26,12 +26,6 @@ commands=py.test
 deps =
     pytest
 
-[testenv:py27-d15]
-basepython = python2.7
-deps =
-    django==1.5.9
-    {[testenv]deps}
-
 [testenv:py27-d16]
 basepython = python2.7
 deps =
@@ -44,8 +38,8 @@ deps =
     django==1.7
     {[testenv]deps}
 
-[testenv:py33-d17]
-basepython = python3.3
+[testenv:py34-d17]
+basepython = python3.4
 deps =
     django==1.7
     {[testenv]deps}