diff --git a/NEWS b/NEWS
index 480b2cb..c2d450b 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,8 @@ v1.12.1 (8th Jan 2014)
 * #176: Fix AttributeError bugs in known_hosts file (re)loading. Thanks to
   Nathan Scowcroft for the patch & Martin Blumenstingl for the initial test
   case.
+* #225: Note ecdsa requirement in README. Thanks to Amaury Rodriguez for the
+  catch.
 
 v1.11.3 (8th Jan 2014)
 ----------------------
diff --git a/README b/README
index 9f68d37..0933467 100644
--- a/README
+++ b/README
@@ -36,6 +36,7 @@ Requirements
 
   - python 2.5 or better <http://www.python.org/>
   - pycrypto 2.1 or better <https://www.dlitz.net/software/pycrypto/>
+  - ecdsa 0.9 or better <https://pypi.python.org/pypi/ecdsa>
 
 If you have setuptools, you can build and install paramiko and all its
 dependencies with this command (as root)::