diff --git a/inputs/test/test_containers.py b/inputs/test/test_containers.py
index 5417e69a..4786053c 100644
--- a/inputs/test/test_containers.py
+++ b/inputs/test/test_containers.py
@@ -2,12 +2,12 @@
 
 import os
 import pathlib
-import socket
 import subprocess
 import tempfile
 
 import pytest
 
+from osbuild import testutil
 from osbuild.testutil import has_executable, make_container
 
 INPUTS_NAME = "org.osbuild.containers-storage"
@@ -40,8 +40,8 @@ def test_containers_local_inputs_integration(tmp_path, inputs_module):
                 }
             }
         }
-        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        cnt_inputs = inputs_module.ContainersStorageInput.from_args(["--service-fd", str(sock.fileno())])
+        fd = testutil.make_fake_service_fd()
+        cnt_inputs = inputs_module.ContainersStorageInput.from_args(["--service-fd", str(fd)])
         store = FakeStoreClient(tmp_path / "fake-sources")
         # not using "tmp_path" here as it will "rm -rf" on cleanup and
         # that is dangerous as during the tests we bind mount the
diff --git a/osbuild/testutil/__init__.py b/osbuild/testutil/__init__.py
index a5b69327..e5e1a1fe 100644
--- a/osbuild/testutil/__init__.py
+++ b/osbuild/testutil/__init__.py
@@ -6,6 +6,7 @@ import os
 import pathlib
 import re
 import shutil
+import socket
 import subprocess
 import tempfile
 import textwrap
@@ -155,3 +156,15 @@ def pull_oci_archive_container(archive_path, image_name):
         yield
     finally:
         subprocess.check_call(["skopeo", "delete", f"containers-storage:{image_name}"])
+
+
+def make_fake_service_fd() -> int:
+    """Create a file descriptor suitable as input for --service-fd for any
+    host.Service
+
+    Note that the service will take over the fd and take care of the
+    lifecycle so no need to close it.
+    """
+    sock = socket.socket(socket.AF_UNIX, socket.SOCK_SEQPACKET)
+    fd = os.dup(sock.fileno())
+    return fd
diff --git a/sources/test/test_container_storage_source.py b/sources/test/test_container_storage_source.py
index 7eeec1ce..140ab985 100644
--- a/sources/test/test_container_storage_source.py
+++ b/sources/test/test_container_storage_source.py
@@ -1,11 +1,11 @@
 #!/usr/bin/python3
 
 import os
-import socket
 import subprocess
 
 import pytest
 
+from osbuild import testutil
 from osbuild.testutil import has_executable, make_container
 
 SOURCES_NAME = "org.osbuild.containers-storage"
@@ -20,8 +20,8 @@ def test_containers_storage_integration(tmp_path, sources_module):
         image_id = subprocess.check_output(["podman", "inspect", "-f", "{{ .Id }}", base_tag],
                                            universal_newlines=True).strip()
         checksum = f"sha256:{image_id}"
-        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(sock.fileno())])
+        fd = testutil.make_fake_service_fd()
+        cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(fd)])
         assert cnt_storage.exists(checksum, None)
 
 
@@ -29,8 +29,8 @@ def test_containers_storage_integration(tmp_path, sources_module):
 @pytest.mark.skipif(os.getuid() != 0, reason="root only")
 def test_containers_storage_integration_missing(sources_module):
     checksum = "sha256:1234567890123456789012345678901234567890909b14ffb032aa20fa23d9ad6"
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(fd)])
     assert not cnt_storage.exists(checksum, None)
 
 
@@ -40,8 +40,8 @@ def test_containers_storage_integration_invalid(sources_module):
     # put an invalid reference into the source to ensure skopeo errors with
     # a different error than image not found
     checksum = "sha256:["
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    cnt_storage = sources_module.ContainersStorageSource.from_args(["--service-fd", str(fd)])
     with pytest.raises(RuntimeError) as exc:
         cnt_storage.exists(checksum, None)
     assert "unknown skopeo error:" in str(exc)
diff --git a/sources/test/test_curl_source.py b/sources/test/test_curl_source.py
index a65a4018..267b668e 100644
--- a/sources/test/test_curl_source.py
+++ b/sources/test/test_curl_source.py
@@ -3,17 +3,18 @@
 import contextlib
 import os
 import pathlib
-import socket
 import tempfile
 
 import pytest
 
+from osbuild import testutil
+
 SOURCES_NAME = "org.osbuild.curl"
 
 
 def test_curl_source_not_exists(sources_module):
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(fd)])
     tmpdir = tempfile.TemporaryDirectory()
     curl_source.cache = tmpdir.name
     desc = {
@@ -24,8 +25,8 @@ def test_curl_source_not_exists(sources_module):
 
 
 def test_curl_source_exists(sources_module):
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(fd)])
     tmpdir = tempfile.TemporaryDirectory()
     curl_source.cache = tmpdir.name
     desc = {
@@ -37,8 +38,8 @@ def test_curl_source_exists(sources_module):
 
 
 def test_curl_source_amend_secrets(sources_module):
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(fd)])
     tmpdir = tempfile.TemporaryDirectory()
     curl_source.cache = tmpdir.name
     desc = {
@@ -65,8 +66,8 @@ def test_curl_source_amend_secrets(sources_module):
 
 
 def test_curl_source_amend_secrets_fail(sources_module):
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(sock.fileno())])
+    fd = testutil.make_fake_service_fd()
+    curl_source = sources_module.CurlSource.from_args(["--service-fd", str(fd)])
     tmpdir = tempfile.TemporaryDirectory()
     curl_source.cache = tmpdir.name
     desc = {