diff --git a/pkg/model/annotation.go b/pkg/model/annotation.go
index ed0ceffa90..a7dfc820ea 100644
--- a/pkg/model/annotation.go
+++ b/pkg/model/annotation.go
@@ -16,8 +16,8 @@ var (
 )
 
 type Annotation struct {
-	AppName   string    `gorm:"not null;default:null"`
-	Timestamp time.Time `form:"not null;default:null"`
+	AppName   string    `gorm:"index:idx_appname_timestamp,unique;not null;default:null"`
+	Timestamp time.Time `gorm:"index:idx_appname_timestamp,unique;not null;default:null"`
 	Content   string    `gorm:"not null;default:null"`
 	CreatedAt time.Time
 	UpdatedAt time.Time
diff --git a/pkg/service/annotation.go b/pkg/service/annotation.go
index 476461e7e8..d7316f5b6d 100644
--- a/pkg/service/annotation.go
+++ b/pkg/service/annotation.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/pyroscope-io/pyroscope/pkg/model"
 	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
 )
 
 type AnnotationsService struct{ db *gorm.DB }
@@ -30,11 +31,17 @@ func (svc AnnotationsService) CreateAnnotation(ctx context.Context, params model
 	tx := svc.db.WithContext(ctx)
 
 	// Upsert
-	if tx.Where(model.CreateAnnotation{
-		AppName:   params.AppName,
-		Timestamp: params.Timestamp,
-	}).Updates(&u).RowsAffected == 0 {
-		return &u, tx.Create(&u).Error
+	if err := tx.Clauses(clause.OnConflict{
+		Columns: []clause.Column{
+			{Name: "app_name"},
+			{Name: "timestamp"},
+		},
+		// Update fields we care about
+		DoUpdates: clause.AssignmentColumns([]string{"app_name", "timestamp", "content"}),
+		// Update updateAt fields
+		UpdateAll: true,
+	}).Create(&u).Error; err != nil {
+		return nil, err
 	}
 
 	return &u, nil
diff --git a/pkg/service/annotation_test.go b/pkg/service/annotation_test.go
index 55c1efe905..faa0f1e3d9 100644
--- a/pkg/service/annotation_test.go
+++ b/pkg/service/annotation_test.go
@@ -34,7 +34,7 @@ var _ = Describe("AnnotationsService", func() {
 			Expect(annotation).ToNot(BeNil())
 			Expect(annotation.AppName).To(Equal("myapp"))
 			Expect(annotation.Content).To(Equal("mycontent"))
-			Expect(annotation.Timestamp).To(Equal(now))
+			Expect(annotation.Timestamp.Unix()).To(Equal(now.Unix()))
 
 			Expect(annotation.CreatedAt).ToNot(BeZero())
 			Expect(annotation.UpdatedAt).ToNot(BeZero())
diff --git a/pkg/sqlstore/migrations/migrations.go b/pkg/sqlstore/migrations/migrations.go
index 02b77a1273..b867a7f20b 100644
--- a/pkg/sqlstore/migrations/migrations.go
+++ b/pkg/sqlstore/migrations/migrations.go
@@ -49,6 +49,7 @@ func Migrate(db *gorm.DB, c *config.Server) error {
 		createUserTableMigration(c.Auth.Internal.AdminUser),
 		createAPIKeyTableMigration(),
 		createAnnotationsTableMigration(),
+		addIndexesUniqueTableMigration(),
 	}).Migrate()
 }
 
@@ -132,3 +133,20 @@ func createAnnotationsTableMigration() *gormigrate.Migration {
 		},
 	}
 }
+
+func addIndexesUniqueTableMigration() *gormigrate.Migration {
+	type annotation struct {
+		AppName   string    `gorm:"index:idx_appname_timestamp,unique;not null;default:null"`
+		Timestamp time.Time `gorm:"index:idx_appname_timestamp,unique;not null;default:null"`
+	}
+
+	return &gormigrate.Migration{
+		ID: "1663269650",
+		Migrate: func(tx *gorm.DB) error {
+			return tx.AutoMigrate(&annotation{})
+		},
+		Rollback: func(tx *gorm.DB) error {
+			return tx.Migrator().DropIndex(&annotation{}, "idx_appname_timestamp")
+		},
+	}
+}