diff --git a/test_libs/pyspec/eth2spec/utils/ssz/ssz_impl.py b/test_libs/pyspec/eth2spec/utils/ssz/ssz_impl.py
index 8b6c20a17..79675fb4a 100644
--- a/test_libs/pyspec/eth2spec/utils/ssz/ssz_impl.py
+++ b/test_libs/pyspec/eth2spec/utils/ssz/ssz_impl.py
@@ -104,7 +104,7 @@ def hash_tree_root(obj, typ=None):
         leaf_root = merkleize_chunks(leaves)
         return mix_in_length(leaf_root, len(obj)) if is_list_type(typ) else leaf_root
     elif is_container_typ(typ):
-        leaves = [hash_tree_root(elem, subtyp) for elem, subtyp in zip(obj.get_field_values(), typ.get_field_types())]
+        leaves = [hash_tree_root(elem, subtyp) for elem, subtyp in obj.get_fields().items()]
         return merkleize_chunks(chunkify(b''.join(leaves)))
     else:
         raise Exception("Type not supported: obj {} type {}".format(obj, typ))
@@ -113,11 +113,11 @@ def signing_root(value, typ):
     if typ is None:
         typ = infer_type(obj)
     assert is_container_typ(typ)
-    leaves = [hash_tree_root(elem, subtyp) for elem, subtyp in zip(obj.get_field_values(), typ.get_field_types())[:-1]]
+    leaves = [hash_tree_root(elem, subtyp) for elem, subtyp in obj.get_fields().items()]
     return merkleize_chunks(chunkify(b''.join(leaves)))
 
 # Implementation notes:
-# - SSZContainer,Vector/BytesN.hash_tree_root/serialize functions are for ease, implementation here
+# - Container,Vector/BytesN.hash_tree_root/serialize functions are for ease, implementation here
 # - uint types have a 'byte_len' attribute
 # - uint types are not classes. They use NewType(), for performance.
 #    This forces us to check type equivalence by exact reference.
diff --git a/test_libs/pyspec/eth2spec/utils/ssz/ssz_typing.py b/test_libs/pyspec/eth2spec/utils/ssz/ssz_typing.py
index 78c82be45..76e518e64 100644
--- a/test_libs/pyspec/eth2spec/utils/ssz/ssz_typing.py
+++ b/test_libs/pyspec/eth2spec/utils/ssz/ssz_typing.py
@@ -30,7 +30,7 @@ byte = NewType('byte', uint8)
 
 # Note: importing ssz functionality locally, to avoid import loop
 
-class SSZContainer(object):
+class Container(object):
 
     def __init__(self, **kwargs):
         cls = self.__class__
@@ -291,7 +291,7 @@ def get_zero_value(typ):
         return typ()
     if issubclass(typ, bytes):
         return b''
-    if issubclass(typ, SSZContainer):
+    if issubclass(typ, Container):
         return typ(**{f: get_zero_value(t) for f, t in typ.get_fields().items()}),
 
 # Type helpers
@@ -304,7 +304,7 @@ def infer_type(obj):
         return uint64
     elif isinstance(obj, list):
         return List[infer_type(obj[0])]
-    elif isinstance(obj, (Vector, SSZContainer, bool, BytesN, bytes)):
+    elif isinstance(obj, (Vector, Container, bool, BytesN, bytes)):
         return obj.__class__
     else:
         raise Exception("Unknown type for {}".format(obj))