diff --git a/README.md b/README.md
index 5839691..4e4d058 100644
--- a/README.md
+++ b/README.md
@@ -115,17 +115,26 @@ Sometimes, elm-package flakes out due to connection issues. The simplest solutio
 with_retry.rb elm-package install
 ```
 
-
 ## elm_self_publish
 
 Sometimes, we want to "install" our packages locally to test them before publishing them remotely. This is designed only with the use case of testing packaged, not using them in production. It doesn't provide any of the guarantees nor support that elm-package does. If you're doing production stuff, elm-package is what you want.
 
-
 ```
 python elm_self_publish.py ../elm-css ../json-to-elm/
 ```
 
 will publish elm-css into json-to-elm
 
+## Upgrading a Python dependency
+
+If you have Nix, you can load a shell with the necessary dependencies like this:
+
+```
+nix-shell -p python37Packages.pip-tools
+```
 
+Once in the shell, run:
 
+```
+pip-compile --upgrade-package my-package
+```
diff --git a/requirements.txt b/requirements.txt
index b639c58..184882e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,4 +8,4 @@ certifi==2018.11.29       # via requests
 chardet==3.0.4            # via requests
 idna==2.8                 # via requests
 requests==2.21.0
-urllib3==1.24.1           # via requests
+urllib3==1.24.3