diff --git a/fields/types/relationship/Readme.md b/fields/types/relationship/Readme.md
index 9c3a6961e67..0065ff83fc0 100644
--- a/fields/types/relationship/Readme.md
+++ b/fields/types/relationship/Readme.md
@@ -53,6 +53,8 @@ Will return unexpected results if the relationship path has been populated.
 
 Updates with the provided value if it is different from the stored value.
 
+`undefined` values are ignored.
+
 When `null` is passed, mongoose will remove the path from the stored document and the value will be `undefined` when the item is next retrieved. This behaviour is different in `many` mode, when an empty array will be stored.
 
 ### `validateInput`
diff --git a/fields/types/relationship/RelationshipType.js b/fields/types/relationship/RelationshipType.js
index c545462f8f3..a3b0006876d 100644
--- a/fields/types/relationship/RelationshipType.js
+++ b/fields/types/relationship/RelationshipType.js
@@ -219,10 +219,15 @@ relationship.prototype.updateItem = function (item, data, callback) {
 	if (item.populated(this.path)) {
 		throw new Error('fieldTypes.relationship.updateItem() Error - You cannot update populated relationships.');
 	}
+
+	var value = this.getValueFromData(data);
+	if (value === undefined) {
+		return process.nextTick(callback);
+	}
 	if (this.many) {
 		var arr = item.get(this.path);
 		var _old = arr.map(function (i) { return String(i); });
-		var _new = data[this.path];
+		var _new = value;
 		if (!utils.isArray(_new)) {
 			_new = String(_new || '').split(',');
 		}
@@ -232,9 +237,9 @@ relationship.prototype.updateItem = function (item, data, callback) {
 			item.set(this.path, _new);
 		}
 	} else {
-		if (data[this.path]) {
-			if (data[this.path] !== item.get(this.path)) {
-				item.set(this.path, data[this.path]);
+		if (value) {
+			if (value !== item.get(this.path)) {
+				item.set(this.path, value);
 			}
 		} else if (item.get(this.path)) {
 			item.set(this.path, null);
diff --git a/fields/types/relationship/test/type.js b/fields/types/relationship/test/type.js
index cd537a28950..88aca2db4a3 100644
--- a/fields/types/relationship/test/type.js
+++ b/fields/types/relationship/test/type.js
@@ -187,7 +187,7 @@ exports.testFieldType = function (List) {
 			});
 		});
 
-		it('should clear the current value when data object does not contain the field', function (done) {
+		it('should not clear the current value when data object does not contain the field', function (done) {
 			var testItem = new List.model({
 				single: relatedItem.id,
 			});
@@ -195,7 +195,7 @@ exports.testFieldType = function (List) {
 				List.fields.single.updateItem(testItem, {}, function () {
 					testItem.save(function (err, updatedItem) {
 						List.model.findById(updatedItem.id, function (err, persistedData) {
-							demand(persistedData.single).be.null();
+							demand(String(persistedData.single)).equal(String(relatedItem.id));
 							done();
 						});
 					});
@@ -247,7 +247,7 @@ exports.testFieldType = function (List) {
 			});
 		});
 
-		it('should clear the current values when data object does not contain the field', function (done) {
+		it('should not clear the current values when data object does not contain the field', function (done) {
 			var testItem = new List.model({
 				many: [relatedItem.id, relatedItem.id],
 			});
@@ -255,7 +255,9 @@ exports.testFieldType = function (List) {
 				List.fields.many.updateItem(testItem, {}, function () {
 					testItem.save(function (err, updatedItem) {
 						List.model.findById(updatedItem.id, function (err, persistedData) {
-							demand(persistedData.many).to.eql([]);
+							demand(persistedData.many.length).equal(2);
+							demand(String(persistedData.many[0])).equal(String(relatedItem.id));
+							demand(String(persistedData.many[1])).equal(String(relatedItem.id));
 							done();
 						});
 					});