diff --git a/tests/atf_python/sys/netlink/attrs.py b/tests/atf_python/sys/netlink/attrs.py
index 58fbab7fc8db..9769ef0fc76f 100644
--- a/tests/atf_python/sys/netlink/attrs.py
+++ b/tests/atf_python/sys/netlink/attrs.py
@@ -21,7 +21,7 @@ def __init__(self, nla_type, data):
 
     @property
     def nla_type(self):
-        return self._nla_type & 0x3F
+        return self._nla_type & 0x3FFF
 
     @property
     def nla_len(self):
diff --git a/tests/atf_python/sys/netlink/message.py b/tests/atf_python/sys/netlink/message.py
index b6fb2f8e357a..1e2b71775102 100644
--- a/tests/atf_python/sys/netlink/message.py
+++ b/tests/atf_python/sys/netlink/message.py
@@ -205,7 +205,7 @@ def parse_attrs(self, data: bytes, attr_map):
                         nla_len, len(data) - off
                     )
                 )
-            nla_type = raw_nla_type & 0x3F
+            nla_type = raw_nla_type & 0x3FFF
             if nla_type in attr_map:
                 v = attr_map[nla_type]
                 val = v["ad"].cls.from_bytes(data[off:off + nla_len], v["ad"].val)