diff --git a/webapi/src/main/java/org/sakaiproject/webapi/controllers/RubricsRestController.java b/webapi/src/main/java/org/sakaiproject/webapi/controllers/RubricsRestController.java
index 06dfcf9dc47a..721ea7590075 100644
--- a/webapi/src/main/java/org/sakaiproject/webapi/controllers/RubricsRestController.java
+++ b/webapi/src/main/java/org/sakaiproject/webapi/controllers/RubricsRestController.java
@@ -347,6 +347,7 @@ ResponseEntity patchEvaluation(@PathVariable String siteId, @PathVariable Long e
         return rubricsService.getEvaluation(evaluationId, siteId).map(evaluation -> {
 
             ObjectMapper objectMapper = new ObjectMapper();
+            objectMapper.registerModule(new JavaTimeModule());
 
             try {
                 JsonNode patched = patch.apply(objectMapper.convertValue(evaluation, JsonNode.class));
diff --git a/webcomponents/tool/src/main/frontend/packages/sakai-rubrics/src/SakaiRubricStudentButton.js b/webcomponents/tool/src/main/frontend/packages/sakai-rubrics/src/SakaiRubricStudentButton.js
index 28cf6aeee50c..6814ac546756 100644
--- a/webcomponents/tool/src/main/frontend/packages/sakai-rubrics/src/SakaiRubricStudentButton.js
+++ b/webcomponents/tool/src/main/frontend/packages/sakai-rubrics/src/SakaiRubricStudentButton.js
@@ -90,16 +90,16 @@ export class SakaiRubricStudentButton extends rubricsApiMixin(RubricsElement) {
 
       return null;
     })
-    .then(async data => {
-
-      const evaluation = data._embedded.evaluations[0];
+    .then(async evaluation => {
       if (evaluation) {
-        evaluation.status = 2;
+        const evaluationStatus = 2;
         url = `/api/sites/${this.siteId}/rubric-evaluations/${evaluation.id}`;
         await fetch(url, {
-          body: JSON.stringify(evaluation),
+          body: JSON.stringify([
+            { "op": "replace", "path": "/status", "value": evaluationStatus }
+          ]),
           credentials: "include",
-          headers: { "Content-Type": "application/json" },
+          headers: { "Content-Type": "application/json-patch+json" },
           method: "PATCH",
         })
         .then(r => {