diff --git a/requirements.txt b/requirements.txt
index 7c5c1fd..a45ecef 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 graphenelib==0.4.8
 requests==2.10.0
 scrypt==0.7.1
-ecdsa==0.13
+ecdsa==0.13.3
 websockets
diff --git a/setup.py b/setup.py
index 9dfe9f1..093e642 100644
--- a/setup.py
+++ b/setup.py
@@ -256,7 +256,7 @@ def run_tests(self):
     packages=find_packages(exclude=(TESTS_DIRECTORY,)),
     install_requires=[
         "graphenelib==0.4.8", "requests==2.10.0",
-        "scrypt==0.7.1", "ecdsa==0.13", "websockets"
+        "scrypt==0.7.1", "ecdsa==0.13.3", "websockets"
         # your module dependencies
     ] + python_version_specific_requires,
     # Allow tests to be run with `python setup.py test'.