diff --git a/diff/diff.go b/diff/diff.go
index 6b317d8..0633c18 100644
--- a/diff/diff.go
+++ b/diff/diff.go
@@ -46,6 +46,7 @@ type twoints struct {
 }
 
 func Diff(o, n []string) []Instruction {
+
 	if len(o) == 0 && len(n) == 0 {
 		return []Instruction{}
 	}
@@ -91,9 +92,7 @@ func Diff(o, n []string) []Instruction {
 	}
 
 	ret := Diff(o[:omax], n[:nmax])
-	if maxl != nmax {
-		ret = append(ret, Instruction{OP_UNCHANGED, n[nmax : maxl-nmax]})
-	}
+	ret = append(ret, Instruction{OP_UNCHANGED, n[nmax : nmax+maxl]})
 	ret = append(ret, Diff(o[omax+maxl:], n[nmax+maxl:])...)
 
 	return ret