diff --git a/manila/api/v1/security_service.py b/manila/api/v1/security_service.py
index dca6add24a..64edcbe538 100644
--- a/manila/api/v1/security_service.py
+++ b/manila/api/v1/security_service.py
@@ -28,6 +28,7 @@ from manila import db
 from manila import exception
 from manila.i18n import _
 from manila import policy
+from manila import utils
 
 
 RESOURCE_NAME = 'security_service'
@@ -106,7 +107,7 @@ class SecurityServiceController(wsgi.Controller):
             security_services = share_nw['security_services']
             del search_opts['share_network_id']
         else:
-            if 'all_tenants' in search_opts and context.is_admin:
+            if context.is_admin and utils.is_all_tenants(search_opts):
                 policy.check_policy(context, RESOURCE_NAME,
                                     'get_all_security_services')
                 security_services = db.security_service_get_all(context)
diff --git a/manila/tests/api/v1/test_security_service.py b/manila/tests/api/v1/test_security_service.py
index 56125b45ef..5dce4b8745 100644
--- a/manila/tests/api/v1/test_security_service.py
+++ b/manila/tests/api/v1/test_security_service.py
@@ -313,6 +313,25 @@ class ShareApiTest(test.TestCase):
             fake_context, fake_context.project_id
         )
 
+    @mock.patch.object(db, 'security_service_get_all', mock.Mock())
+    def test_security_services_list_all_tenants_with_invalid_value(self):
+        req = fakes.HTTPRequest.blank(
+            '/security-services?all_tenants=nerd',
+            use_admin_context=True)
+        self.assertRaises(exception.InvalidInput, self.controller.index, req)
+
+    @mock.patch.object(db, 'security_service_get_all_by_project', mock.Mock())
+    def test_security_services_list_all_tenants_with_value_zero(self):
+        db.security_service_get_all_by_project.return_value = []
+        req = fakes.HTTPRequest.blank(
+            '/security-services?all_tenants=0',
+            use_admin_context=True)
+        res_dict = self.controller.index(req)
+        self.assertEqual({'security_services': []}, res_dict)
+        db.security_service_get_all_by_project.assert_called_once_with(
+            req.environ['manila.context'],
+            req.environ['manila.context'].project_id)
+
     @mock.patch.object(db, 'security_service_get_all_by_project', mock.Mock())
     def test_security_services_list_admin_context_invalid_opts(self):
         db.security_service_get_all_by_project.return_value = [
diff --git a/releasenotes/notes/bug-1777551-security-services-api-all-tenants-fix-e820ec370d7df473.yaml b/releasenotes/notes/bug-1777551-security-services-api-all-tenants-fix-e820ec370d7df473.yaml
new file mode 100644
index 0000000000..c14d5b7e45
--- /dev/null
+++ b/releasenotes/notes/bug-1777551-security-services-api-all-tenants-fix-e820ec370d7df473.yaml
@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    The ``all_tenants`` query parameter in the security services API (GET
+    /v2/{project_id}/security-services) has been fixed to accept 'f',
+    'false', 'off', 'n', 'no', or '0'. Setting the flag to any of these values
+    will retrieve security services only from the requester's project
+    namespace.