diff --git a/requirements-dev.txt b/requirements-dev.txt
index 6db1ebe..ed0df2d 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -2,9 +2,9 @@
 --requirement requirements.txt
 
 # Testing
-pytest==3.4.2
-pytest-cov==2.5.1
+pytest==5.2.1
+pytest-cov==2.8.1
 
 # Documentation
-Sphinx==1.7.1
-sphinx_rtd_theme==0.2.4
+Sphinx==2.2.0
+sphinx_rtd_theme==0.4.3
diff --git a/requirements.txt b/requirements.txt
index 5478065..a2bc012 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
-six==1.11.0
+six==1.12.0
 
diff --git a/setup.py b/setup.py
index e5bea6c..250c74d 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@
 
 setup(
     name='language_tags',
-    version='0.4.7',
+    version='0.5.0',
     url='https://github.com/OnroerendErfgoed/language-tags',
     license='MIT',
     author='Flanders Heritage Agency',