diff --git a/docs/website/requirements.txt b/docs/website/requirements.txt
index 8ff20d5d55..3f5a201c05 100644
--- a/docs/website/requirements.txt
+++ b/docs/website/requirements.txt
@@ -11,11 +11,11 @@ MarkupSafe==1.0
 Pygments==2.2.0
 pytz==2017.3
 recommonmark==0.4.0
-requests==2.18.4
+requests>=2.20.0
 six==1.11.0
 snowballstemmer==1.2.1
 Sphinx==1.6.6
 sphinx-rtd-theme==0.2.4
 sphinxcontrib-websupport==1.0.1
 typing==3.6.2
-urllib3==1.22
+urllib3>=1.23
diff --git a/requirements/dev.txt b/requirements/dev.txt
index f26fa85370..2fec4e732a 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -3,7 +3,7 @@ flake8>=3.3.0
 tox>=2.2.1
 pytest-cov>=2.4.0
 pylint>=1.7.2
-PyYAML==3.12
+PyYAML>=4.2b1
 
 # Test requirements
 pytest>=3.0.7