diff --git a/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryRestController.java b/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryRestController.java
index 80915e1d8..7735de639 100644
--- a/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryRestController.java
+++ b/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryRestController.java
@@ -1313,6 +1313,12 @@ public class RepositoryRestController
       return notFoundResponse(request);
     }
 
+    // Check if this is a @*ToOne relationship and is optional and if not, fail with a 405 Method Not Allowed
+    if((attrMeta.hasAnnotation(ManyToOne.class) && !attrMeta.annotation(ManyToOne.class).optional())
+        || (attrMeta.hasAnnotation(OneToOne.class) && !attrMeta.annotation(OneToOne.class).optional())) {
+      return negotiateResponse(request, HttpStatus.METHOD_NOT_ALLOWED, new HttpHeaders(), null);
+    }
+
     Object linked = attrMeta.get(entity);
     attrMeta.set(null, entity);
 
diff --git a/spring-data-rest-webmvc/src/test/groovy/org/springframework/data/rest/webmvc/spec/RelationshipsSpec.groovy b/spring-data-rest-webmvc/src/test/groovy/org/springframework/data/rest/webmvc/spec/RelationshipsSpec.groovy
index 4a49a03ec..920b64798 100644
--- a/spring-data-rest-webmvc/src/test/groovy/org/springframework/data/rest/webmvc/spec/RelationshipsSpec.groovy
+++ b/spring-data-rest-webmvc/src/test/groovy/org/springframework/data/rest/webmvc/spec/RelationshipsSpec.groovy
@@ -51,8 +51,8 @@ class RelationshipsSpec extends BaseSpec {
   def "cannot delete a required relationship"() {
 
     when:
-    def request = createRequest("DELETE", "address/$addrId/person/$persId", null)
-    def response = controller.deleteLink(request, "address", "$addrId", "person", "$persId")
+    def request = createRequest("DELETE", "address/$addrId/person", null)
+    def response = controller.clearLinks(request, "address", "$addrId", "person")
 
     then:
     response.statusCode == HttpStatus.METHOD_NOT_ALLOWED