diff --git a/src/allmydata/check_results.py b/src/allmydata/check_results.py
index 8c44fd71e..e9ef59bdb 100644
--- a/src/allmydata/check_results.py
+++ b/src/allmydata/check_results.py
@@ -1,8 +1,6 @@
 """Ported to Python 3.
 """
 
-from past.builtins import unicode
-
 from zope.interface import implementer
 from allmydata.interfaces import ICheckResults, ICheckAndRepairResults, \
      IDeepCheckResults, IDeepCheckAndRepairResults, IURI, IDisplayableServer
@@ -64,7 +62,7 @@ class CheckResults(object):
         # unicode.
         if isinstance(summary, bytes):
             summary = unicode(summary, "utf-8")
-        assert isinstance(summary, unicode)  # should be a single string
+        assert isinstance(summary, str)  # should be a single string
         self._summary = summary
         assert not isinstance(report, str) # should be list of strings
         self._report = report
diff --git a/src/allmydata/immutable/upload.py b/src/allmydata/immutable/upload.py
index 22210ad0a..c13970033 100644
--- a/src/allmydata/immutable/upload.py
+++ b/src/allmydata/immutable/upload.py
@@ -5,7 +5,6 @@ Ported to Python 3.
 from __future__ import annotations
 
 from future.utils import native_str
-from past.builtins import long, unicode
 from six import ensure_str
 
 import os, time, weakref, itertools
@@ -57,7 +56,7 @@ from eliot import (
 
 _TOTAL_SHARES = Field.for_types(
     u"total_shares",
-    [int, long],
+    [int, int],
     u"The total number of shares desired.",
 )
 
@@ -104,7 +103,7 @@ _HAPPINESS_MAPPINGS = Field(
 
 _HAPPINESS = Field.for_types(
     u"happiness",
-    [int, long],
+    [int, int],
     u"The computed happiness of a certain placement.",
 )
 
@@ -142,7 +141,7 @@ GET_SHARE_PLACEMENTS = MessageType(
 
 _EFFECTIVE_HAPPINESS = Field.for_types(
     u"effective_happiness",
-    [int, long],
+    [int, int],
     u"The computed happiness value of a share placement map.",
 )
 
@@ -1622,7 +1621,7 @@ class AssistedUploader(object):
         # abbreviated), so if we detect old results, just clobber them.
 
         sharemap = upload_results.sharemap
-        if any(isinstance(v, (bytes, unicode)) for v in sharemap.values()):
+        if any(isinstance(v, (bytes, str)) for v in sharemap.values()):
             upload_results.sharemap = None
 
     def _build_verifycap(self, helper_upload_results):
@@ -1701,7 +1700,7 @@ class BaseUploadable(object):
     def set_default_encoding_parameters(self, default_params):
         assert isinstance(default_params, dict)
         for k,v in default_params.items():
-            precondition(isinstance(k, (bytes, unicode)), k, v)
+            precondition(isinstance(k, (bytes, str)), k, v)
             precondition(isinstance(v, int), k, v)
         if "k" in default_params:
             self.default_encoding_param_k = default_params["k"]
diff --git a/src/allmydata/scripts/tahoe_status.py b/src/allmydata/scripts/tahoe_status.py
index c7f19910b..ef8da35c0 100644
--- a/src/allmydata/scripts/tahoe_status.py
+++ b/src/allmydata/scripts/tahoe_status.py
@@ -24,13 +24,12 @@ def print(*args, **kwargs):
     encoding error handler and then write the result whereas builtin print
     uses the "strict" encoding error handler.
     """
-    from past.builtins import unicode
     out = kwargs.pop("file", None)
     if out is None:
         out = _sys_stdout
     encoding = out.encoding or "ascii"
     def ensafe(o):
-        if isinstance(o, unicode):
+        if isinstance(o, str):
             return o.encode(encoding, errors="replace").decode(encoding)
         return o
     return _print(
diff --git a/src/allmydata/uri.py b/src/allmydata/uri.py
index fccf05db9..34f245ac7 100644
--- a/src/allmydata/uri.py
+++ b/src/allmydata/uri.py
@@ -7,8 +7,6 @@ Methods ending in to_string() are actually to_bytes(), possibly should be fixed
 in follow-up port.
 """
 
-from past.builtins import unicode, long
-
 import re
 from typing import Type
 
@@ -91,7 +89,7 @@ class CHKFileURI(_BaseURI):
     def to_string(self):
         assert isinstance(self.needed_shares, int)
         assert isinstance(self.total_shares, int)
-        assert isinstance(self.size, (int,long))
+        assert isinstance(self.size, int)
 
         return (b'URI:CHK:%s:%s:%d:%d:%d' %
                 (base32.b2a(self.key),
@@ -147,7 +145,7 @@ class CHKFileVerifierURI(_BaseURI):
     def to_string(self):
         assert isinstance(self.needed_shares, int)
         assert isinstance(self.total_shares, int)
-        assert isinstance(self.size, (int,long))
+        assert isinstance(self.size, int)
 
         return (b'URI:CHK-Verifier:%s:%s:%d:%d:%d' %
                 (si_b2a(self.storage_index),
@@ -742,7 +740,7 @@ ALLEGED_IMMUTABLE_PREFIX = b'imm.'
 
 def from_string(u, deep_immutable=False, name=u"<unknown name>"):
     """Create URI from either unicode or byte string."""
-    if isinstance(u, unicode):
+    if isinstance(u, str):
         u = u.encode("utf-8")
     if not isinstance(u, bytes):
         raise TypeError("URI must be unicode string or bytes: %r" % (u,))
@@ -844,7 +842,7 @@ def is_uri(s):
         return False
 
 def is_literal_file_uri(s):
-    if isinstance(s, unicode):
+    if isinstance(s, str):
         s = s.encode("utf-8")
     if not isinstance(s, bytes):
         return False
@@ -853,7 +851,7 @@ def is_literal_file_uri(s):
             s.startswith(ALLEGED_IMMUTABLE_PREFIX + b'URI:LIT:'))
 
 def has_uri_prefix(s):
-    if isinstance(s, unicode):
+    if isinstance(s, str):
         s = s.encode("utf-8")
     if not isinstance(s, bytes):
         return False
@@ -895,9 +893,9 @@ def pack_extension(data):
     pieces = []
     for k in sorted(data.keys()):
         value = data[k]
-        if isinstance(value, (int, long)):
+        if isinstance(value, int):
             value = b"%d" % value
-        if isinstance(k, unicode):
+        if isinstance(k, str):
             k = k.encode("utf-8")
         assert isinstance(value, bytes), k
         assert re.match(br'^[a-zA-Z_\-]+$', k)