diff --git a/specs/validator/beacon_node_oapi.yaml b/specs/validator/beacon_node_oapi.yaml
index e995e9c84..900b8eefa 100644
--- a/specs/validator/beacon_node_oapi.yaml
+++ b/specs/validator/beacon_node_oapi.yaml
@@ -2,7 +2,7 @@ openapi: "3.0.2"
 info:
   title: "Minimal Beacon Node API for Validator"
   description: "A minimal API specification for the beacon node, which enables a validator to connect and perform its obligations on the Ethereum 2.0 phase 0 beacon chain."
-  version: "0.1.1"
+  version: "0.1.2"
   license:
     name: "Apache 2.0"
     url: "https://www.apache.org/licenses/LICENSE-2.0.html"
@@ -421,17 +421,11 @@ components:
                 type: array
                 description: "Branch in the deposit tree."
                 items:
-                  oneOf:
-                    - type: string
-                      format: byte
-                      pattern: "^0x[a-fA-F0-9]{64}$"
-                    - type: integer
-                      format: uint64
-                      enum: [32]
-                      example: 32
-                      description: "The DEPOSIT_CONTRACT_TREE_DEPTH value."
-                minItems: 2
-                maxItems: 2
+                  type: string
+                  format: byte
+                  pattern: "^0x[a-fA-F0-9]{64}$"
+                minItems: 32
+                maxItems: 32
               index:
                 type: integer
                 format: uint64