--- a/src/xml.rs	Sun Nov 22 17:50:18 2020 +0900
+++ b/src/xml.rs	Sun Nov 22 18:05:42 2020 +0900
@@ -108,6 +108,7 @@
 
     pub fn backing(&mut self, backing_file: &str) -> &mut Builder {
         self.backing_file = backing_file.to_string();
+        self.is_backing = true;
         self
     }
 
@@ -198,37 +199,6 @@
                     writer.write_event(Event::Empty(elem)).ok();
                 }
 
-                // use template qcow2
-                Ok(Event::End(ref e)) if ((e.name() == b"disk") && self.is_backing) => {
-                    let mut backing_store_start = BytesStart::borrowed_name(b"backingStore");
-                    backing_store_start.push_attribute(("type", "file"));
-                    backing_store_start.push_attribute(("index", "3"));
-                    writer
-                        .write_event(Event::Empty(backing_store_start))
-                        .unwrap();
-
-                    writer.write(b"\n").unwrap();
-
-                    let mut format_elem = BytesStart::borrowed_name(b"format");
-                    format_elem.push_attribute(("type", "qcow2"));
-                    writer.write_event(Event::Empty(format_elem)).unwrap();
-                    writer.write(b"\n").unwrap();
-
-                    let mut backing_sorce = BytesStart::borrowed_name(b"sorce");
-                    let backing_file: &str = &self.backing_file;
-                    backing_sorce.push_attribute(("file", backing_file));
-                    writer.write_event(Event::Empty(backing_sorce)).unwrap();
-                    writer.write(b"\n").unwrap();
-
-                    let backing_store_end = BytesEnd::borrowed(b"backingStore");
-                    writer.write_event(Event::End(backing_store_end)).unwrap();
-                    writer.write(b"\n").unwrap();
-
-                    let disk_end = BytesEnd::borrowed(b"disk");
-                    writer.write_event(Event::End(disk_end)).unwrap();
-                    writer.write(b"\n").unwrap();
-                }
-
                 // replace qcow2 file
                 Ok(Event::Empty(ref e)) if (e.name() == b"source") => {
                     let mut elem = e.clone();
@@ -241,6 +211,37 @@
                         elem.push_attribute(("file", qcow2_path));
                     }
                     writer.write_event(Event::Empty(elem)).ok();
+
+                    // use template qcow2
+                    if self.is_backing {
+                        let mut backing_store_start = BytesStart::borrowed_name(b"backingStore");
+                        backing_store_start.push_attribute(("type", "file"));
+                        backing_store_start.push_attribute(("index", "3"));
+                        writer
+                            .write_event(Event::Empty(backing_store_start))
+                            .unwrap();
+
+                        writer.write(b"\n").unwrap();
+
+                        let mut format_elem = BytesStart::borrowed_name(b"format");
+                        format_elem.push_attribute(("type", "qcow2"));
+                        writer.write_event(Event::Empty(format_elem)).unwrap();
+                        writer.write(b"\n").unwrap();
+
+                        let mut backing_sorce = BytesStart::borrowed_name(b"sorce");
+                        let backing_file: &str = &self.backing_file;
+                        backing_sorce.push_attribute(("file", backing_file));
+                        writer.write_event(Event::Empty(backing_sorce)).unwrap();
+                        writer.write(b"\n").unwrap();
+
+                        let backing_store_end = BytesEnd::borrowed(b"backingStore");
+                        writer.write_event(Event::End(backing_store_end)).unwrap();
+                        writer.write(b"\n").unwrap();
+
+                        let disk_end = BytesEnd::borrowed(b"disk");
+                        writer.write_event(Event::End(disk_end)).unwrap();
+                        writer.write(b"\n").unwrap();
+                    }
                 }
 
                 Ok(Event::Text(ref e)) if e.escaped() == IE_VIRSH_TEMPLATE_VM_NAME.as_bytes() => {