diff --git a/writer.go b/writer.go
index f4d20b0..b4d5722 100644
--- a/writer.go
+++ b/writer.go
@@ -227,7 +227,7 @@ func (this *PdfWriter) endObj() {
 
 func (this *PdfWriter) shaOfInt(i int) string {
 	hasher := sha1.New()
-	hasher.Write([]byte(fmt.Sprintf("%s-%s", i, this.r.sourceFile)))
+	hasher.Write([]byte(fmt.Sprintf("%s-%s-%s", this.tpl_id_offset, i, this.r.sourceFile)))
 	sha := hex.EncodeToString(hasher.Sum(nil))
 	return sha
 }