diff --git a/descriptor.md b/descriptor.md
index 8b7fe61e8..de7d38f17 100644
--- a/descriptor.md
+++ b/descriptor.md
@@ -23,7 +23,7 @@ The following describe the primary set of properties that make up a _Descriptor_
   This REQUIRED property is the _digest_ of the targeted content, meeting the requirements outlined in [Digests and Verification](#digests-and—verification).
   Retrieved content SHOULD be verified against this digest when consumed via untrusted sources.
 
-- **`size`** *int*
+- **`size`** *int64*
   This REQUIRED property specifies the size in bytes of the blob.
   This property exists so that a client will have an expected size for the content before validating.
   If the length of the retrieved content does not match the specified length, the content SHOULD NOT be trusted.
diff --git a/schema/content-descriptor.json b/schema/content-descriptor.json
index c4bdb6bde..2e6ceba9b 100644
--- a/schema/content-descriptor.json
+++ b/schema/content-descriptor.json
@@ -10,7 +10,7 @@
     },
     "size": {
       "description": "the size in bytes of the referenced object",
-      "type": "integer"
+      "$ref": "defs.json#/definitions/int64"
     },
     "digest": {
       "$ref": "defs-image.json#definitions/digest"
diff --git a/schema/defs-image.json b/schema/defs-image.json
index d0d6b780e..3c3e708f0 100644
--- a/schema/defs-image.json
+++ b/schema/defs-image.json
@@ -27,7 +27,7 @@
         },
         "size": {
           "description": "the size in bytes of the referenced object",
-          "type": "integer"
+          "$ref": "defs.json#/definitions/int64"
         },
         "digest": {
           "$ref": "#definitions/digest"