fix mattmann affil.
diff --git a/contributors.md b/contributors.md
index 5b716b5..68c4584 100644
--- a/contributors.md
+++ b/contributors.md
@@ -12,7 +12,7 @@
- [Adam Pauls](http://www.eecs.berkeley.edu/~adpauls/) (Berkeley)
- [Chris Callison-Burch](http://cs.jhu.edu/~ccb/) (Penn)
- [Chris Dyer](http://www.cs.cmu.edu/~cdyer/) (Carnegie Mellon)
-- [Chris Mattmann](http://sunset.usc.edu/~mattmann/) (APL, USC)
+- [Chris Mattmann](http://sunset.usc.edu/~mattmann/) (NASA JPL, USC)
- [Colin Bannard](http://comp.ling.utexas.edu/~bannard/) (UT Austin)
- [Jonathan Weese](http://cs.jhu.edu/~jonny/) (Johns Hopkins)
- Josh Schroeder (Edinburgh)
