diff --git a/requirements.txt b/requirements.txt
index af50f5a..d052cd3 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,4 +3,4 @@ ws4py
 secp256k1
 graphenelib==0.4.8
 scrypt==0.7.1
-ecdsa==0.13
+ecdsa==0.13.3
diff --git a/setup.py b/setup.py
index a19fa4e..131c14e 100644
--- a/setup.py
+++ b/setup.py
@@ -258,7 +258,7 @@ def run_tests(self):
         'secp256k1',
         "graphenelib==0.4.8",
         "scrypt==0.7.1",
-        "ecdsa==0.13"
+        "ecdsa==0.13.3"
         # your module dependencies
     ] + python_version_specific_requires,
     # Allow tests to be run with `python setup.py test'.