diff --git a/api-ref/source/os-security-groups.inc b/api-ref/source/os-security-groups.inc
index 9714dff23ae4..3838d97a006e 100644
--- a/api-ref/source/os-security-groups.inc
+++ b/api-ref/source/os-security-groups.inc
@@ -35,6 +35,7 @@ Request
 
   - limit: limit_simple
   - offset: offset_simple
+  - all_tenants: all_tenants_sec_grp_query
 
 Response
 --------
diff --git a/api-ref/source/parameters.yaml b/api-ref/source/parameters.yaml
index 00f99189cac7..e09e9073ca64 100644
--- a/api-ref/source/parameters.yaml
+++ b/api-ref/source/parameters.yaml
@@ -385,6 +385,15 @@ all_tenants_query:
   in: query
   required: false
   type: integer
+all_tenants_sec_grp_query:
+  description: |
+    Specify the ``all_tenants`` query parameter to list all security
+    groups for all projects. This is only allowed for admin users.
+    Value of this query parameter is not checked, only presence
+    is considered as request for all tenants.
+  in: query
+  required: false
+  type: string
 availability_zone_query_server:
   description: |
     Filter the server list result by server availability zone.