diff --git a/requirements.txt b/requirements.txt
index c6d6121..abf7f3d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,5 +11,5 @@ M2Crypto<1.0.0
 wsgiref<1.0.0
 pyasn1<1.0.0
 pyasn1-modules<1.0.0
-rfc3161=0.1.6
+rfc3161==0.1.6
 psycopg2<2.5.0