diff --git a/backend/requirements.txt b/backend/requirements.txt
index 2ae6d15..f94b709 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -7,7 +7,7 @@ chardet==3.0.4
 Click==7.0
 cryptography==2.6.1
 cytoolz==0.9.0.1
-ecdsa==0.13
+ecdsa==0.13.3
 eth-abi==1.3.0
 eth-account==0.3.0
 eth-hash==0.2.0