diff --git a/src/binary/config.rs b/src/binary/config.rs
index 6ace741..6562fde 100644
--- a/src/binary/config.rs
+++ b/src/binary/config.rs
@@ -29,13 +29,7 @@ impl ArchivalConfig {
 
     pub fn get() -> Self {
         match Self::from_fs() {
-            Ok(config) => {
-                if let Some(config) = config {
-                    config
-                } else {
-                    ArchivalConfig::default()
-                }
-            }
+            Ok(config) => config.unwrap_or_default(),
             Err(e) => {
                 eprintln!("config parse failed, using default value. ({})", e);
                 ArchivalConfig::default()
diff --git a/src/object/object_entry.rs b/src/object/object_entry.rs
index 6a5221e..b4072c6 100644
--- a/src/object/object_entry.rs
+++ b/src/object/object_entry.rs
@@ -84,12 +84,12 @@ impl<'a> Iterator for ObjectEntryMutIterator<'a> {
             ObjectEntry::List(l) => {
                 let o = l.get_mut(self.index);
                 self.index += 1;
-                unsafe { std::mem::transmute(o) }
+                unsafe { std::mem::transmute::<Option<&mut Object>, Option<&mut Object>>(o) }
             }
             ObjectEntry::Object(o) => {
                 if self.index == 0 {
                     self.index = usize::MAX;
-                    unsafe { std::mem::transmute(o) }
+                    unsafe { std::mem::transmute::<&mut Object, Option<&mut Object>>(o) }
                 } else {
                     None
                 }