diff --git a/requirements.txt b/requirements.txt
index 21ec01b3..5e27ff5d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 pycryptodome
 six
 rsa
-ecdsa<0.15
+ecdsa != 0.15
 pyasn1