diff --git a/systemd.spec b/systemd.spec
index b0ce180..ff42fbb 100644
--- a/systemd.spec
+++ b/systemd.spec
@@ -64,6 +64,7 @@ Source0:        https://github.com/systemd/systemd/archive/v%{version_no_tilde}/
 Source1:        triggers.systemd
 Source2:        split-files.py
 Source3:        purge-nobody-user
+Source4:        test_sysusers_defined.py
 
 # Prevent accidental removal of the systemd package
 Source5:        yum-protect-systemd.conf
@@ -271,6 +272,11 @@ Conflicts:      initscripts < 9.56.1
 %if 0%{?fedora}
 Conflicts:      fedora-release < 23-0.12
 %endif
+%if 0%{?fedora} >= 41
+BuildRequires:  setup >= 2.15.0-3
+BuildRequires:  python3
+Conflicts:      setup < 2.15.0-3
+%endif
 
 %if 0%{?fedora} >= 41
 # Make sure that dracut supports systemd-executor and the renames done for v255,
@@ -926,6 +932,13 @@ ln -s --relative %{buildroot}%{_bindir}/kernel-install %{buildroot}%{_sbindir}/i
 mv -v %{buildroot}/usr/sbin/* %{buildroot}%{_bindir}/
 %endif
 
+%if 0%{?fedora} >= 41
+# This requires https://pagure.io/setup/pull-request/50
+# and https://src.fedoraproject.org/rpms/setup/pull-request/10.
+%{python3} %{SOURCE4} /usr/lib/sysusers.d/20-setup-{users,groups}.conf %{buildroot}/usr/lib/sysusers.d/basic.conf
+rm %{buildroot}/usr/lib/sysusers.d/basic.conf
+%endif
+
 %find_lang %{name}
 
 # Split files in build root into rpms
diff --git a/test_sysusers_defined.py b/test_sysusers_defined.py
new file mode 100755
index 0000000..2754578
--- /dev/null
+++ b/test_sysusers_defined.py
@@ -0,0 +1,34 @@
+#!/usr/bin/python
+
+import sys
+
+def parse_sysusers_file(filename):
+    users, groups = set(), set()
+
+    for line in open(filename):
+        line = line.strip()
+        if not line or line.startswith('#'):
+            continue
+        words = line.split()
+        match words[0]:
+            case 'u':
+                users.add(words[1])
+            case 'g':
+                groups.add(words[1])
+            case 'm'|'r':
+                continue
+            case _:
+                assert False
+    return users, groups
+
+setup_users, setup_groups = parse_sysusers_file(sys.argv[1])
+setup_users2, setup_groups2 = parse_sysusers_file(sys.argv[2])
+setup_users |= setup_users2
+setup_groups |= setup_groups2
+
+basic_users, basic_groups = parse_sysusers_file(sys.argv[3])
+
+if d := basic_users - setup_users:
+    exit(f'We have new users: {d}')
+if d := basic_groups - setup_groups:
+    exit(f'We have new groups: {d}')