diff --git a/specification/apis/pki/pki.api.v1.simpleenroll.json b/specification/apis/pki/pki.api.v1.simpleenroll.json
index 42d9574..ef5b4d5 100644
--- a/specification/apis/pki/pki.api.v1.simpleenroll.json
+++ b/specification/apis/pki/pki.api.v1.simpleenroll.json
@@ -50,7 +50,18 @@
                     ],
                     "default": "secp256r1",
                     "example": "secp521r1"
-              }
+              },
+              {
+                  "name": "cpoV2GRootCertificateFingerprint",
+                  "in": "path",
+                  "description": "Defines the V2G PKI which shall be used for the EVSE simpleEnrollment."
+                  "schema": {
+                        "type": "string",
+                        "pattern": "^[0-9a-fA-F]{64}$",
+                        "example": "311f28ff13da6d75f836ac10644b34273da99564c600a191fb3737d50562a4f1"
+                   }
+                }
+        },
         ],
         "requestBody": {
             "content": {