diff --git a/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt b/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt
index d50bcbb5..1bf8bff4 100644
--- a/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt
+++ b/src/main/kotlin/org/neo4j/graphql/handler/MergeOrUpdateHandler.kt
@@ -67,13 +67,8 @@ class MergeOrUpdateHandler private constructor(
     }
 
     init {
-        defaultFields.clear() // for marge or updates we do not reset to defaults
-        if (idField.isNativeId() || merge) {
-            // native id cannot be updated
-            // if the ID is not a native ID and we are in the update mode, we do not remove it from the properties
-            // b/c otherwise the id field will be unset
-            propertyFields.remove(idField.name)
-        }
+        defaultFields.clear() // for merge or updates we do not reset to defaults
+        propertyFields.remove(idField.name) // id should not be updated
     }
 
     override fun generateCypher(variable: String, field: Field, env: DataFetchingEnvironment): Cypher {
@@ -82,10 +77,9 @@ class MergeOrUpdateHandler private constructor(
         val properties = properties(variable, field.arguments)
         val mapProjection = projectFields(variable, field, type, env, null)
 
-        val op = if (merge) "+" else ""
         val select = getSelectQuery(variable, label(), idArg, idField, isRelation)
         return Cypher((if (merge && !idField.isNativeId()) "MERGE " else "MATCH ") + select.query +
-                " SET $variable $op= " + properties.query +
+                " SET $variable += " + properties.query +
                 " WITH $variable" +
                 " RETURN ${mapProjection.query} AS $variable",
                 select.params + properties.params + mapProjection.params)
diff --git a/src/test/resources/dynamic-property-tests.adoc b/src/test/resources/dynamic-property-tests.adoc
index 3dcb1323..4c0b1a07 100644
--- a/src/test/resources/dynamic-property-tests.adoc
+++ b/src/test/resources/dynamic-property-tests.adoc
@@ -104,8 +104,7 @@ mutation {
 [source,cypher]
 ----
 MATCH (updatePerson:Person { id: $updatePersonId })
-SET updatePerson = {
-  id: $updatePersonId,
+SET updatePerson += {
   `properties.foo`: $updatePersonJsonFoo,
   `properties.x`: $updatePersonJsonX
 }
@@ -209,7 +208,7 @@ mutation {
 ----
 MATCH ()-[updateKnows:KNOWS]->()
 WHERE ID(updateKnows) = toInteger($updateKnows_id)
-SET updateKnows = { `prefix.foo`: $updateKnowsJsonFoo }
+SET updateKnows += { `prefix.foo`: $updateKnowsJsonFoo }
 WITH updateKnows
 RETURN updateKnows {
   json:apoc.map.fromPairs([key IN keys(updateKnows) WHERE key STARTS WITH 'prefix.'| [substring(key,7), updateKnows[key]]])
diff --git a/src/test/resources/movie-tests.adoc b/src/test/resources/movie-tests.adoc
index 6f505045..ee63ecc0 100644
--- a/src/test/resources/movie-tests.adoc
+++ b/src/test/resources/movie-tests.adoc
@@ -940,7 +940,7 @@ mutation {
 ----
 MATCH ()-[updateRated:RATED]->()
 WHERE ID(updateRated) = toInteger($updateRated_id)
-SET updateRated = { rating: $updateRatedRating }
+SET updateRated += { rating: $updateRatedRating }
 WITH updateRated
 RETURN updateRated { .rating } AS updateRated
 ----
diff --git a/src/test/resources/translator-tests-custom-scalars.adoc b/src/test/resources/translator-tests-custom-scalars.adoc
index 1095ceed..cc433747 100644
--- a/src/test/resources/translator-tests-custom-scalars.adoc
+++ b/src/test/resources/translator-tests-custom-scalars.adoc
@@ -73,7 +73,7 @@ mutation {
 ----
 MATCH (updateMovie: Movie)
 WHERE ID(updateMovie) = toInteger($updateMovie_id)
-SET updateMovie = { released: $updateMovieReleased }
+SET updateMovie += { released: $updateMovieReleased }
 WITH updateMovie
 RETURN updateMovie { .title, .released } AS updateMovie
 ----
@@ -137,7 +137,7 @@ mutation {
 ----
 MATCH (updateMovie: Movie)
 WHERE ID(updateMovie) = toInteger($updateMovie_id)
-SET updateMovie = { released: $updateMovieReleased }
+SET updateMovie += { released: $updateMovieReleased }
 WITH updateMovie
 RETURN updateMovie { .title, .released } AS updateMovie
 ----