diff --git a/delta/plugins/storage/src/main/scala/ch/epfl/bluebrain/nexus/delta/plugins/storage/files/model/FileEvent.scala b/delta/plugins/storage/src/main/scala/ch/epfl/bluebrain/nexus/delta/plugins/storage/files/model/FileEvent.scala
index f3034a1fb6..4a39ace3e0 100644
--- a/delta/plugins/storage/src/main/scala/ch/epfl/bluebrain/nexus/delta/plugins/storage/files/model/FileEvent.scala
+++ b/delta/plugins/storage/src/main/scala/ch/epfl/bluebrain/nexus/delta/plugins/storage/files/model/FileEvent.scala
@@ -12,6 +12,7 @@ import ch.epfl.bluebrain.nexus.delta.rdf.jsonld.context.JsonLdContext.keywords
 import ch.epfl.bluebrain.nexus.delta.sdk.implicits._
 import ch.epfl.bluebrain.nexus.delta.plugins.storage.instances._
 import ch.epfl.bluebrain.nexus.delta.plugins.storage.storages.StoragesConfig.StorageTypeConfig
+import ch.epfl.bluebrain.nexus.delta.sdk.circe.JsonObjOps
 import ch.epfl.bluebrain.nexus.delta.sdk.jsonld.IriEncoder
 import ch.epfl.bluebrain.nexus.delta.sdk.model.BaseUri
 import ch.epfl.bluebrain.nexus.delta.sdk.model.metrics.EventMetric._
@@ -23,7 +24,7 @@ import ch.epfl.bluebrain.nexus.delta.sourcing.model.Identity.Subject
 import ch.epfl.bluebrain.nexus.delta.sourcing.model.Tag.UserTag
 import ch.epfl.bluebrain.nexus.delta.sourcing.model.{EntityType, Label, ProjectRef, ResourceRef}
 import io.circe.generic.extras.Configuration
-import io.circe.generic.extras.semiauto.{deriveConfiguredCodec, deriveConfiguredEncoder}
+import io.circe.generic.extras.semiauto.{deriveConfiguredCodec, deriveConfiguredDecoder, deriveConfiguredEncoder}
 import io.circe.generic.semiauto.deriveEncoder
 import io.circe.syntax._
 import io.circe.{Codec, Decoder, Encoder, Json}
@@ -266,7 +267,8 @@ object FileEvent {
       deriveConfiguredCodec[Digest]
     implicit val fileAttributesCodec: Codec.AsObject[FileAttributes] =
       deriveConfiguredCodec[FileAttributes]
-    implicit val coder: Codec.AsObject[FileEvent]                    = deriveConfiguredCodec[FileEvent]
+    implicit val enc: Encoder.AsObject[FileEvent]                    = deriveConfiguredEncoder[FileEvent].mapJsonObject(_.dropNulls)
+    implicit val codec: Codec.AsObject[FileEvent]                    = Codec.AsObject.from(deriveConfiguredDecoder, enc)
     Serializer()
   }
 
@@ -335,6 +337,7 @@ object FileEvent {
           }
           deriveConfiguredEncoder[FileEvent]
             .encodeObject(event)
+            .dropNulls
             .remove("storage")
             .remove("storageType")
             .addIfExists("_storage", storageJsonOpt)
diff --git a/delta/plugins/storage/src/test/resources/files/database/file-created.json b/delta/plugins/storage/src/test/resources/files/database/file-created.json
index 16f4154946..4c323ebfe8 100644
--- a/delta/plugins/storage/src/test/resources/files/database/file-created.json
+++ b/delta/plugins/storage/src/test/resources/files/database/file-created.json
@@ -3,7 +3,6 @@
   "project" : "myorg/myproj",
   "storage" : "https://bluebrain.github.io/nexus/vocabulary/disk-storage?rev=1",
   "storageType" : "DiskStorage",
-  "tag" : null,
   "attributes" : {
     "origin" : "Client",
     "uuid" : "8049ba90-7cc6-4de5-93a1-802c04200dcc",
diff --git a/delta/plugins/storage/src/test/resources/files/sse/file-created.json b/delta/plugins/storage/src/test/resources/files/sse/file-created.json
index 5c8ae298dd..1ab5ab912b 100644
--- a/delta/plugins/storage/src/test/resources/files/sse/file-created.json
+++ b/delta/plugins/storage/src/test/resources/files/sse/file-created.json
@@ -4,7 +4,6 @@
     "https://bluebrain.github.io/nexus/contexts/files.json"
   ],
   "@type": "FileCreated",
-  "tag": null,
   "_attributes": {
     "_bytes": 12,
     "_digest": {
diff --git a/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/circe/package.scala b/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/circe/package.scala
index 28f72441e3..c1cd50ffa3 100644
--- a/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/circe/package.scala
+++ b/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/circe/package.scala
@@ -3,7 +3,7 @@ package ch.epfl.bluebrain.nexus.delta.sdk
 import cats.Order
 import cats.data.NonEmptyMap
 import io.circe.syntax.EncoderOps
-import io.circe.{Decoder, Encoder}
+import io.circe.{Decoder, Encoder, JsonObject}
 
 package object circe {
 
@@ -21,4 +21,10 @@ package object circe {
       }
 
   }
+
+  implicit class JsonObjOps(j: JsonObject) {
+    def dropNulls: JsonObject = dropNullValues(j)
+  }
+
+  def dropNullValues(j: JsonObject): JsonObject = j.filter { case (_, v) => !v.isNull }
 }
diff --git a/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/resources/model/ResourceEvent.scala b/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/resources/model/ResourceEvent.scala
index b9784a79e0..9eca75d08a 100644
--- a/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/resources/model/ResourceEvent.scala
+++ b/delta/sdk/src/main/scala/ch/epfl/bluebrain/nexus/delta/sdk/resources/model/ResourceEvent.scala
@@ -5,6 +5,7 @@ import ch.epfl.bluebrain.nexus.delta.rdf.Vocabulary.{contexts, nxv}
 import ch.epfl.bluebrain.nexus.delta.rdf.jsonld.context.ContextValue
 import ch.epfl.bluebrain.nexus.delta.rdf.jsonld.context.JsonLdContext.keywords
 import ch.epfl.bluebrain.nexus.delta.rdf.jsonld.{CompactedJsonLd, ExpandedJsonLd}
+import ch.epfl.bluebrain.nexus.delta.sdk.circe.{dropNullValues, JsonObjOps}
 import ch.epfl.bluebrain.nexus.delta.sdk.instances._
 import ch.epfl.bluebrain.nexus.delta.sdk.jsonld.IriEncoder
 import ch.epfl.bluebrain.nexus.delta.sdk.model.BaseUri
@@ -340,7 +341,7 @@ object ResourceEvent {
       implicit val projectRefEncoder: Encoder[ProjectRef] = IriEncoder.jsonEncoder[ProjectRef]
       Encoder.encodeJsonObject.contramapObject { event =>
         val obj = deriveConfiguredEncoder[ResourceEvent].encodeObject(event)
-        dropNullValues(obj)
+        obj.dropNulls
           .remove("compacted")
           .remove("expanded")
           .remove("remoteContexts")
@@ -348,6 +349,4 @@ object ResourceEvent {
       }
     }
   }
-
-  private def dropNullValues(j: JsonObject): JsonObject = j.filter { case (_, v) => !v.isNull }
 }