diff --git a/endpoints/openrtb2/sample-requests/invalid-whole/cache-nothing.json b/endpoints/openrtb2/sample-requests/invalid-whole/cache-nothing.json
index d4b875498ae..f256e4eb34c 100644
--- a/endpoints/openrtb2/sample-requests/invalid-whole/cache-nothing.json
+++ b/endpoints/openrtb2/sample-requests/invalid-whole/cache-nothing.json
@@ -1,5 +1,5 @@
 {
-  "message": "Invalid request: request.ext is invalid: request.ext.prebid.cache requires one of the \"bids\" or \"vastml\" properties\n",
+  "message": "Invalid request: request.ext is invalid: request.ext.prebid.cache requires one of the \"bids\" or \"vastxml\" properties\n",
   "requestPayload": {
     "id": "some-request-id",
     "site": {
diff --git a/openrtb_ext/request.go b/openrtb_ext/request.go
index 23daaf0f76e..d6edf47f939 100644
--- a/openrtb_ext/request.go
+++ b/openrtb_ext/request.go
@@ -67,7 +67,7 @@ func (ert *ExtRequestPrebidCache) UnmarshalJSON(b []byte) error {
 	}
 
 	if proxy.Bids == nil && proxy.VastXML == nil {
-		return errors.New(`request.ext.prebid.cache requires one of the "bids" or "vastml" properties`)
+		return errors.New(`request.ext.prebid.cache requires one of the "bids" or "vastxml" properties`)
 	}
 
 	*ert = ExtRequestPrebidCache(proxy)