diff --git a/specs/openapi.json b/specs/openapi.json
index 4e57106..4f4c387 100644
--- a/specs/openapi.json
+++ b/specs/openapi.json
@@ -13290,6 +13290,7 @@
                 "properties": {
                   "external_user_id": {
                     "type": "string",
+                    "minLength": 1,
                     "maxLength": 1024
                   },
                   "preferred_global_name": {
diff --git a/specs/openapi_preview.json b/specs/openapi_preview.json
index 841e97d..feb6fd6 100644
--- a/specs/openapi_preview.json
+++ b/specs/openapi_preview.json
@@ -13302,6 +13302,7 @@
                 "properties": {
                   "external_user_id": {
                     "type": "string",
+                    "minLength": 1,
                     "maxLength": 1024
                   },
                   "preferred_global_name": {