diff --git a/README.md b/README.md
index 58a25cb..bcfb1f3 100644
--- a/README.md
+++ b/README.md
@@ -20,8 +20,10 @@ and do not need to be memorized.
 
 ```$ pip install magic-wormhole```
 
-On Debian/Ubuntu systems, you may first need `apt-get python-dev libffi-dev`.
-On OS-X, you may need to install `pip`.
+On Debian/Ubuntu systems, you may first need `apt-get python-dev
+libffi-dev`. On Fedora it's `libffi-devel` and `python-devel`. On OS-X,
+you may need to install `pip` and run `xcode-select --install` to get
+GCC.
 
 Developers can clone the source tree and run `tox` to run the unit tests on
 all supported (and installed) versions of python: 2.7, 3.3, 3.4, and 3.5.