diff --git a/features/pool/pool.go b/features/pool/pool.go
index 64d4ba5..efb0f41 100644
--- a/features/pool/pool.go
+++ b/features/pool/pool.go
@@ -68,7 +68,7 @@ func (p *pool) message(message *protogen.Message) {
 			}
 			p.P(fmt.Sprintf("f%d", len(saved)), ` := m.`, fieldName, `[:0]`)
 			saved = append(saved, field)
-		} else if field.Oneof != nil {
+		} else if field.Oneof != nil && !field.Oneof.Desc.IsSynthetic() {
 			if p.ShouldPool(field.Message) {
 				p.P(`if oneof, ok := m.`, field.Oneof.GoName, `.(*`, field.GoIdent, `); ok {`)
 				p.P(`oneof.`, fieldName, `.ReturnToVTPool()`)