diff --git a/requirements-docs.txt b/requirements-docs.txt
index 33df8bf..9e17a4f 100644
--- a/requirements-docs.txt
+++ b/requirements-docs.txt
@@ -4,34 +4,67 @@
 #
 #    pip-compile --output-file=requirements-docs.txt requirements-docs.in
 #
-alabaster==0.7.12         # via sphinx
-babel==2.7.0              # via sphinx
-certifi==2019.9.11        # via requests
-chardet==3.0.4            # via requests
-docutils==0.15.2          # via sphinx
-idna==2.8                 # via requests
-imagesize==1.1.0          # via sphinx
-jinja2==2.10.3            # via sphinx
+alabaster==0.7.12
+    # via sphinx
+babel==2.9.1
+    # via sphinx
+certifi==2019.9.11
+    # via requests
+chardet==3.0.4
+    # via requests
+docutils==0.15.2
+    # via sphinx
+idna==2.8
+    # via requests
+imagesize==1.1.0
+    # via sphinx
+jinja2==2.10.3
+    # via sphinx
 livereload==2.6.1
-markupsafe==1.1.1         # via jinja2
-packaging==19.2           # via sphinx
-pygments==2.4.2           # via sphinx
-pyparsing==2.4.2          # via packaging
-pytz==2019.3              # via babel
-requests==2.22.0          # via sphinx
-six==1.12.0               # via livereload, packaging
-snowballstemmer==2.0.0    # via sphinx
+    # via -r requirements-docs.in
+markupsafe==1.1.1
+    # via jinja2
+packaging==19.2
+    # via sphinx
+pygments==2.4.2
+    # via sphinx
+pyparsing==2.4.2
+    # via packaging
+pytz==2019.3
+    # via babel
+requests==2.22.0
+    # via sphinx
+six==1.12.0
+    # via
+    #   livereload
+    #   packaging
+snowballstemmer==2.0.0
+    # via sphinx
+sphinx==2.2.0
+    # via
+    #   -r requirements-docs.in
+    #   sphinx-autodoc-typehints
+    #   sphinx-rtd-theme
 sphinx-autodoc-typehints==1.8.0
+    # via -r requirements-docs.in
 sphinx-rtd-theme==0.4.3
-sphinx==2.2.0
-sphinxcontrib-applehelp==1.0.1  # via sphinx
-sphinxcontrib-devhelp==1.0.1  # via sphinx
-sphinxcontrib-htmlhelp==1.0.2  # via sphinx
-sphinxcontrib-jsmath==1.0.1  # via sphinx
-sphinxcontrib-qthelp==1.0.2  # via sphinx
-sphinxcontrib-serializinghtml==1.1.3  # via sphinx
-tornado==6.0.3            # via livereload
-urllib3==1.25.6           # via requests
+    # via -r requirements-docs.in
+sphinxcontrib-applehelp==1.0.1
+    # via sphinx
+sphinxcontrib-devhelp==1.0.1
+    # via sphinx
+sphinxcontrib-htmlhelp==1.0.2
+    # via sphinx
+sphinxcontrib-jsmath==1.0.1
+    # via sphinx
+sphinxcontrib-qthelp==1.0.2
+    # via sphinx
+sphinxcontrib-serializinghtml==1.1.3
+    # via sphinx
+tornado==6.0.3
+    # via livereload
+urllib3==1.25.6
+    # via requests
 
 # The following packages are considered to be unsafe in a requirements file:
-# setuptools==41.4.0        # via sphinx
+# setuptools