diff --git a/requirements.txt b/requirements.txt
index 3bed7ed..1a3ed2a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 limnoria > 2012.08.04 # Needs MultipleReplacer, from 1a64f105
 psutil >= 3.1.0 # Fixes #640
+ecdsa