diff --git a/setup.py b/setup.py
index f1811f3..1f3eb21 100644
--- a/setup.py
+++ b/setup.py
@@ -44,16 +44,15 @@ def read(*rnames):
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
-        "Programming Language :: Python :: Implementation",
         "Programming Language :: Python :: Implementation :: CPython",
         "Programming Language :: Python :: Implementation :: PyPy",
         "Natural Language :: English",
         "Operating System :: OS Independent",
         "Topic :: Software Development :: Libraries :: Python Modules",
         "Framework :: Plone",
-        "Framework :: Zope",
         "Framework :: Zope :: 2",
         "Framework :: Zope :: 3",
+        "Framework :: Zope :: 4",
     ],
     keywords="zpt template zope",
     url="https://github.com/zopefoundation/z3c.ptcompat",
diff --git a/tools/update.py b/tools/update.py
index 7ff27f3..1852631 100755
--- a/tools/update.py
+++ b/tools/update.py
@@ -124,7 +124,8 @@ def main(options, args):
         output, err = proc.communicate("\n".join(diffs) + "\n")
 
         if proc.returncode != 0:
-            map(status, output.split("\n"))
+            for line in output.split("\n"):
+                status(line)
             status("An error occurred while applying patches.")
             break
     else:
@@ -145,13 +146,12 @@ def create_diff(filename):
         new = exp.sub(replacement, new)
 
     if original != new:
-        return "\n".join(
-            map(
-                str.rstrip,
-                difflib.unified_diff(
-                    original.split("\n"), new.split("\n"), filename, filename
-                ),
-            )
+        return ''.join(
+            difflib.unified_diff(
+                original.splitlines(True),
+                new.splitlines(True),
+                filename,
+                filename)
         )