diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
index 0fe456aa7..e4a4b0868 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoOperations.java
@@ -1258,11 +1258,13 @@ public interface MongoOperations extends FluentMongoOperations {
* Spring's
* Type Conversion" for more details.
*
- *
* Insert is used to initially store the object into the database. To update an existing object use the save method.
+ *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @return the inserted object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
T insert(T objectToSave);
@@ -1273,10 +1275,13 @@ public interface MongoOperations extends FluentMongoOperations {
* configured otherwise, an instance of {@link MappingMongoConverter} will be used.
*
* Insert is used to initially store the object into the database. To update an existing object use the save method.
+ *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @param collectionName name of the collection to store the object in. Must not be {@literal null}.
* @return the inserted object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
T insert(T objectToSave, String collectionName);
@@ -1320,11 +1325,11 @@ public interface MongoOperations extends FluentMongoOperations {
* Spring's
* Type Conversion" for more details.
*
- * The {@literal objectToSave} must not be collection like.
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @return the saved object.
- * @throws IllegalArgumentException in case the objectToSave is collection like.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
T save(T objectToSave);
@@ -1341,13 +1346,12 @@ public interface MongoOperations extends FluentMongoOperations {
* https://docs.spring.io/spring/docs/current/spring-framework-reference/core.html#validation">Spring's Type
* Conversion" for more details.
*
- * The {@literal objectToSave} must not be collection like.
- *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @param collectionName name of the collection to store the object in. Must not be {@literal null}.
* @return the saved object.
- * @throws IllegalArgumentException in case the objectToSave is collection like.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
T save(T objectToSave, String collectionName);
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
index a1a0925b7..fb1c26030 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/ReactiveMongoOperations.java
@@ -1038,11 +1038,13 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
* Spring's
* Type Conversion" for more details.
*
- *
* Insert is used to initially store the object into the database. To update an existing object use the save method.
+ *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @return the inserted object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
Mono insert(T objectToSave);
@@ -1053,10 +1055,13 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
* configured otherwise, an instance of {@link MappingMongoConverter} will be used.
*
* Insert is used to initially store the object into the database. To update an existing object use the save method.
+ *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @param collectionName name of the collection to store the object in. Must not be {@literal null}.
* @return the inserted object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
Mono insert(T objectToSave, String collectionName);
@@ -1098,7 +1103,6 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
* Spring's
* Type Conversion" for more details.
*
- *
* Insert is used to initially store the object into the database. To update an existing object use the save method.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
@@ -1145,9 +1149,12 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
* property type will be handled by Spring's BeanWrapper class that leverages Type Conversion API. See
* Spring's
* Type Conversion" for more details.
+ *
+ * The {@code objectToSave} must not be collection-like.
*
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @return the saved object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
Mono save(T objectToSave);
@@ -1167,6 +1174,7 @@ public interface ReactiveMongoOperations extends ReactiveFluentMongoOperations {
* @param objectToSave the object to store in the collection. Must not be {@literal null}.
* @param collectionName name of the collection to store the object in. Must not be {@literal null}.
* @return the saved object.
+ * @throws IllegalArgumentException in case the {@code objectToSave} is collection-like.
*/
Mono save(T objectToSave, String collectionName);