diff --git a/reader.go b/reader.go
index 4b82493..e9e1ed9 100644
--- a/reader.go
+++ b/reader.go
@@ -85,7 +85,7 @@ func (rd *Reader) octal(b []byte) int64 {
 		i--
 	}
 
-	n, _ := strconv.ParseInt(string(b[3:i+1]), 8, 64)
+	n, _ := strconv.ParseInt(string(b[0:i+1]), 8, 64)
 
 	return n
 }
diff --git a/reader_test.go b/reader_test.go
index a2657f5..a43d590 100644
--- a/reader_test.go
+++ b/reader_test.go
@@ -58,7 +58,7 @@ func TestReadHeader(t *testing.T) {
 	if header.Gid != expectedGid {
 		t.Errorf("Gid should be %s but is %s", expectedGid, header.Gid)
 	}
-	expectedMode := int64(0644)
+	expectedMode := int64(0100644)
 	if header.Mode != expectedMode {
 		t.Errorf("Mode should be %s but is %s", expectedMode, header.Mode)
 	}