diff --git a/session.go b/session.go
index 009a758a..91037457 100644
--- a/session.go
+++ b/session.go
@@ -651,6 +651,7 @@ func (session *Session) cacheGet(bean interface{}, sqlStr string, args ...interf
 			if v, ok := data[session.Statement.RefTable.PrimaryKeys[0]]; !ok {
 				return false, ErrCacheFailed
 			} else {
+				// TODO https://github.com/go-xorm/xorm/issues/144, PK may not always be int64
 				id, err = strconv.ParseInt(string(v), 10, 64)
 				if err != nil {
 					return false, err