1 files changed, 2 insertions, 1 deletions
diff --git a/README.md b/README.md
index e58d912c..cb91db67 100755
--- a/README.md
+++ b/README.md
@@ -57,7 +57,8 @@ pip install -U cmd2
 ```
 
 cmd2 works with Python 3.4+ on Windows, macOS, and Linux. It is pure Python code with
-the only 3rd-party dependencies being on [colorama](https://github.com/tartley/colorama), and [pyperclip](https://github.com/asweigart/pyperclip).
+the only 3rd-party dependencies being on [attrs](https://github.com/python-attrs/attrs), 
+[colorama](https://github.com/tartley/colorama), and [pyperclip](https://github.com/asweigart/pyperclip).
 Windows has an additional dependency on [pyreadline](https://pypi.python.org/pypi/pyreadline). Non-Windows platforms
 have an additional dependency on [wcwidth](https://pypi.python.org/pypi/wcwidth). Finally, Python
 3.4 has an additional dependency on [contextlib2](https://pypi.python.org/pypi/contextlib2).