diff --git a/staging/src/k8s.io/apiserver/pkg/audit/request.go b/staging/src/k8s.io/apiserver/pkg/audit/request.go
index 57a10e62b026..30755a8a5683 100644
--- a/staging/src/k8s.io/apiserver/pkg/audit/request.go
+++ b/staging/src/k8s.io/apiserver/pkg/audit/request.go
@@ -239,7 +239,7 @@ func encodeObject(obj runtime.Object, gv schema.GroupVersion, serializer runtime
 
 	return &runtime.Unknown{
 		Raw:         buf.Bytes(),
-		ContentType: runtime.ContentTypeJSON,
+		ContentType: mediaType,
 	}, nil
 }
 
diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/delete.go b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/delete.go
index 3da06721dfb6..542400a00cb9 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/delete.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/delete.go
@@ -103,7 +103,7 @@ func DeleteResource(r rest.GracefulDeleter, allowsOptions bool, scope *RequestSc
 				trace.Step("Decoded delete options")
 
 				objGV := gvk.GroupVersion()
-				audit.LogRequestObject(req.Context(), obj, objGV, scope.Resource, scope.Subresource, scope.Serializer)
+				audit.LogRequestObject(req.Context(), obj, objGV, scope.Resource, scope.Subresource, metainternalversionscheme.Codecs)
 				trace.Step("Recorded the audit event")
 			} else {
 				if err := metainternalversionscheme.ParameterCodec.DecodeParameters(req.URL.Query(), scope.MetaGroupVersion, options); err != nil {
@@ -238,8 +238,8 @@ func DeleteCollection(r rest.CollectionDeleter, checkBody bool, scope *RequestSc
 				}
 				// For backwards compatibility, we need to allow existing clients to submit per group DeleteOptions
 				// It is also allowed to pass a body with meta.k8s.io/v1.DeleteOptions
-				defaultGVK := scope.Kind.GroupVersion().WithKind("DeleteOptions")
-				obj, gvk, err := scope.Serializer.DecoderToVersion(s.Serializer, defaultGVK.GroupVersion()).Decode(body, &defaultGVK, options)
+				defaultGVK := scope.MetaGroupVersion.WithKind("DeleteOptions")
+				obj, gvk, err := metainternalversionscheme.Codecs.DecoderToVersion(s.Serializer, defaultGVK.GroupVersion()).Decode(body, &defaultGVK, options)
 				if err != nil {
 					scope.err(err, w, req)
 					return
@@ -250,7 +250,7 @@ func DeleteCollection(r rest.CollectionDeleter, checkBody bool, scope *RequestSc
 				}
 
 				objGV := gvk.GroupVersion()
-				audit.LogRequestObject(req.Context(), obj, objGV, scope.Resource, scope.Subresource, scope.Serializer)
+				audit.LogRequestObject(req.Context(), obj, objGV, scope.Resource, scope.Subresource, metainternalversionscheme.Codecs)
 			} else {
 				if err := metainternalversionscheme.ParameterCodec.DecodeParameters(req.URL.Query(), scope.MetaGroupVersion, options); err != nil {
 					err = errors.NewBadRequest(err.Error())