diff --git a/sslscan/module/rating/builtin.py b/sslscan/module/rating/builtin.py
index 7afb10b..18cfb11 100644
--- a/sslscan/module/rating/builtin.py
+++ b/sslscan/module/rating/builtin.py
@@ -50,6 +50,7 @@ def __init__(self, **kwargs):
                 rules=[
                     lambda v, i, kb: 6 if v.startswith("md2") else None,
                     lambda v, i, kb: 6 if v.startswith("md5") else None,
+                    lambda v, i, kb: 3 if v.startswith("sha1") else None,
                 ]
             )
         )