diff --git a/callbacks/create.go b/callbacks/create.go
index 10da731f..909d984a 100644
--- a/callbacks/create.go
+++ b/callbacks/create.go
@@ -353,15 +353,14 @@ func ConvertToCreateValues(stmt *gorm.Statement) (values clause.Values) {
 					}
 				}
 
-				onConflict := clause.OnConflict{
-					Columns:   make([]clause.Column, len(stmt.Schema.PrimaryFieldDBNames)),
-					DoUpdates: clause.AssignmentColumns(columns),
-				}
+				onConflict.DoUpdates = clause.AssignmentColumns(columns)
 
-				for idx, field := range stmt.Schema.PrimaryFields {
-					onConflict.Columns[idx] = clause.Column{Name: field.DBName}
+				// use primary fields as default OnConflict columns
+				if len(onConflict.Columns) == 0 {
+					for _, field := range stmt.Schema.PrimaryFields {
+						onConflict.Columns = append(onConflict.Columns, clause.Column{Name: field.DBName})
+					}
 				}
-
 				stmt.AddClause(onConflict)
 			}
 		}