diff --git a/server/src/api/v1/upload_path.rs b/server/src/api/v1/upload_path.rs
index 3673797..4b04601 100644
--- a/server/src/api/v1/upload_path.rs
+++ b/server/src/api/v1/upload_path.rs
@@ -46,7 +46,7 @@ use crate::database::entity::cache;
 use crate::database::entity::chunk::{self, ChunkState, Entity as Chunk};
 use crate::database::entity::chunkref::{self, Entity as ChunkRef};
 use crate::database::entity::nar::{self, Entity as Nar, NarState};
-use crate::database::entity::object::{self, Entity as Object};
+use crate::database::entity::object::{self, Entity as Object, InsertExt};
 use crate::database::entity::Json as DbJson;
 use crate::database::{AtticDatabase, ChunkGuard, NarGuard};
 
@@ -257,12 +257,6 @@ async fn upload_path_dedup(
         .map_err(ServerError::database_error)?;
 
     // Create a mapping granting the local cache access to the NAR
-    Object::delete_many()
-        .filter(object::Column::CacheId.eq(cache.id))
-        .filter(object::Column::StorePathHash.eq(upload_info.store_path_hash.to_string()))
-        .exec(&txn)
-        .await
-        .map_err(ServerError::database_error)?;
     Object::insert({
         let mut new_object = upload_info.to_active_model();
         new_object.cache_id = Set(cache.id);
@@ -271,6 +265,7 @@ async fn upload_path_dedup(
         new_object.created_by = Set(username);
         new_object
     })
+    .on_conflict_do_update()
     .exec(&txn)
     .await
     .map_err(ServerError::database_error)?;
@@ -487,12 +482,6 @@ async fn upload_path_new_chunked(
     .map_err(ServerError::database_error)?;
 
     // Create a mapping granting the local cache access to the NAR
-    Object::delete_many()
-        .filter(object::Column::CacheId.eq(cache.id))
-        .filter(object::Column::StorePathHash.eq(upload_info.store_path_hash.to_string()))
-        .exec(&txn)
-        .await
-        .map_err(ServerError::database_error)?;
     Object::insert({
         let mut new_object = upload_info.to_active_model();
         new_object.cache_id = Set(cache.id);
@@ -501,6 +490,7 @@ async fn upload_path_new_chunked(
         new_object.created_by = Set(username);
         new_object
     })
+    .on_conflict_do_update()
     .exec(&txn)
     .await
     .map_err(ServerError::database_error)?;
@@ -594,12 +584,6 @@ async fn upload_path_new_unchunked(
     .map_err(ServerError::database_error)?;
 
     // Create a mapping granting the local cache access to the NAR
-    Object::delete_many()
-        .filter(object::Column::CacheId.eq(cache.id))
-        .filter(object::Column::StorePathHash.eq(upload_info.store_path_hash.to_string()))
-        .exec(&txn)
-        .await
-        .map_err(ServerError::database_error)?;
     Object::insert({
         let mut new_object = upload_info.to_active_model();
         new_object.cache_id = Set(cache.id);
@@ -608,6 +592,7 @@ async fn upload_path_new_unchunked(
         new_object.created_by = Set(username);
         new_object
     })
+    .on_conflict_do_update()
     .exec(&txn)
     .await
     .map_err(ServerError::database_error)?;
diff --git a/server/src/database/entity/object.rs b/server/src/database/entity/object.rs
index 37ad893..69b5a62 100644
--- a/server/src/database/entity/object.rs
+++ b/server/src/database/entity/object.rs
@@ -6,6 +6,8 @@ use std::path::PathBuf;
 use std::str::FromStr;
 
 use sea_orm::entity::prelude::*;
+use sea_orm::sea_query::OnConflict;
+use sea_orm::Insert;
 
 use super::nar::NarModel;
 use super::Json;
@@ -15,6 +17,10 @@ use attic::hash::Hash;
 
 pub type ObjectModel = Model;
 
+pub trait InsertExt {
+    fn on_conflict_do_update(self) -> Self;
+}
+
 /// An object in a binary cache.
 #[derive(Debug, Clone, PartialEq, Eq, DeriveEntityModel)]
 #[sea_orm(table_name = "object")]
@@ -87,6 +93,27 @@ pub enum Relation {
     Nar,
 }
 
+impl InsertExt for Insert<ActiveModel> {
+    fn on_conflict_do_update(self) -> Self {
+        self.on_conflict(
+            OnConflict::columns([Column::CacheId, Column::StorePathHash])
+                .update_columns([
+                    Column::NarId,
+                    Column::StorePath,
+                    Column::References,
+                    Column::System,
+                    Column::Deriver,
+                    Column::Sigs,
+                    Column::Ca,
+                    Column::CreatedAt,
+                    Column::LastAccessedAt,
+                    Column::CreatedBy,
+                ])
+                .to_owned(),
+        )
+    }
+}
+
 impl Model {
     /// Converts this object to a NarInfo.
     pub fn to_nar_info(&self, nar: &NarModel) -> ServerResult<NarInfo> {