diff --git a/conftest.py b/conftest.py
index d6a595b8..3aedc2ba 100644
--- a/conftest.py
+++ b/conftest.py
@@ -267,7 +267,7 @@ def local_sr_on_hostB1(hostB1):
 def existing_shared_sr(host):
     sr = host.pool.first_shared_sr()
     assert sr is not None, "A shared SR on the pool is required"
-    return sr
+    yield sr
 
 @pytest.fixture(scope='session')
 def sr_disk(pytestconfig, host):
diff --git a/tests/uefi_sb/test_uefistored_sb.py b/tests/uefi_sb/test_uefistored_sb.py
index 60e5df8c..059cfdf8 100644
--- a/tests/uefi_sb/test_uefistored_sb.py
+++ b/tests/uefi_sb/test_uefistored_sb.py
@@ -4,9 +4,9 @@
 from lib.commands import SSHCommandFailed
 from lib.common import wait_for
 
-from .utils import test_key_exchanges, boot_and_check_no_sb_errors, boot_and_check_sb_failed, \
+from .utils import _test_key_exchanges, boot_and_check_no_sb_errors, boot_and_check_sb_failed, \
     boot_and_check_sb_succeeded, generate_keys, revert_vm_state, sign_efi_bins, VM_SECURE_BOOT_FAILED, \
-    test_uefi_var_migrate
+    _test_uefi_var_migrate
 
 # These tests check the behaviour of XAPI and uefistored as they are in XCP-ng 8.2
 # For XCP-ng 8.3 or later, see test_varstored_sb.py
@@ -217,7 +217,7 @@ def setup_and_cleanup(self, uefi_vm_and_snapshot):
     def test_key_exchanges(self, uefi_vm):
         vm = uefi_vm
 
-        test_key_exchanges(vm)
+        _test_key_exchanges(vm)
 
 @pytest.mark.small_vm
 @pytest.mark.usefixtures("host_less_than_8_3", "existing_shared_sr")
@@ -230,4 +230,4 @@ def setup_and_cleanup(self, uefi_vm_and_snapshot):
         revert_vm_state(vm, snapshot)
 
     def test_uefi_var_migrate(self, host, hostA2, uefi_vm):
-        test_uefi_var_migrate(uefi_vm, host, hostA2)
+        _test_uefi_var_migrate(uefi_vm, host, hostA2)
diff --git a/tests/uefi_sb/test_varstored_sb.py b/tests/uefi_sb/test_varstored_sb.py
index d610f040..fc83e43b 100644
--- a/tests/uefi_sb/test_varstored_sb.py
+++ b/tests/uefi_sb/test_varstored_sb.py
@@ -1,8 +1,8 @@
 import logging
 import pytest
 
-from .utils import test_key_exchanges, boot_and_check_no_sb_errors, boot_and_check_sb_failed, \
-    boot_and_check_sb_succeeded, generate_keys, revert_vm_state, sign_efi_bins, test_uefi_var_migrate
+from .utils import _test_key_exchanges, boot_and_check_no_sb_errors, boot_and_check_sb_failed, \
+    boot_and_check_sb_succeeded, generate_keys, revert_vm_state, sign_efi_bins, _test_uefi_var_migrate
 
 # These tests check the behaviour of XAPI and varstored as they are in XCP-ng 8.3
 # For XCP-ng 8.2, see test_uefistored_sb.py
@@ -152,7 +152,7 @@ def test_key_exchanges(self, uefi_vm):
         vm = uefi_vm
         vm.set_uefi_setup_mode()
 
-        test_key_exchanges(vm)
+        _test_key_exchanges(vm)
 
 @pytest.mark.small_vm
 @pytest.mark.usefixtures("host_at_least_8_3", "existing_shared_sr")
@@ -164,4 +164,4 @@ def setup_and_cleanup(self, uefi_vm_and_snapshot):
         revert_vm_state(vm, snapshot)
 
     def test_uefi_var_migrate(self, host, hostA2, uefi_vm):
-        test_uefi_var_migrate(uefi_vm, host, hostA2)
+        _test_uefi_var_migrate(uefi_vm, host, hostA2)
diff --git a/tests/uefi_sb/utils.py b/tests/uefi_sb/utils.py
index 7ff10fba..4ffb783f 100644
--- a/tests/uefi_sb/utils.py
+++ b/tests/uefi_sb/utils.py
@@ -84,7 +84,7 @@ def sign_efi_bins(vm, db):
     if shutdown:
         vm.shutdown(verify=True)
 
-def test_key_exchanges(vm):
+def _test_key_exchanges(vm):
     PK = EFIAuth('PK')
     null_PK = EFIAuth('PK', is_null=True)
     new_PK = EFIAuth('PK')
@@ -174,7 +174,7 @@ def check_vm_cert_md5sum(vm, key, reference_file):
     reference_md5 = get_md5sum_from_auth(reference_file)
     assert hashlib.md5(res.stdout).hexdigest() == reference_md5
 
-def test_uefi_var_migrate(vm, source_host, dest_host):
+def _test_uefi_var_migrate(vm, source_host, dest_host):
     shared_sr = source_host.pool.first_shared_sr()
     vm.clear_uefi_variables()
     pool_auths = generate_keys(as_dict=True)