diff --git a/schemas/input/csl-data.json b/schemas/input/csl-data.json
index ab524472..1f4ae1e3 100644
--- a/schemas/input/csl-data.json
+++ b/schemas/input/csl-data.json
@@ -378,6 +378,9 @@
       "part-title": {
         "type": "string"
       },
+      "ARXIV": {
+        "type": "string"
+      },
       "PMCID": {
         "type": "string"
       },
diff --git a/schemas/styles/csl-variables.rnc b/schemas/styles/csl-variables.rnc
index fe66d5e8..198f6de2 100644
--- a/schemas/styles/csl-variables.rnc
+++ b/schemas/styles/csl-variables.rnc
@@ -114,6 +114,7 @@ div {
     | "note"
     | "original-publisher"
     | "original-publisher-place"
+    | "ARXIV"
     | "PMCID"
     | "PMID"
     | "publisher"