diff --git a/crates/mitex-cli/src/lib.rs b/crates/mitex-cli/src/lib.rs
index 381a4f1..d961afb 100644
--- a/crates/mitex-cli/src/lib.rs
+++ b/crates/mitex-cli/src/lib.rs
@@ -200,11 +200,11 @@ fn process_opts(mut opts: Opts) -> Result<Opts, clap::Error> {
             match io_args.len() {
                 0 => {}
                 1 => {
-                    args.input = io_args[0].clone();
+                    args.input.clone_from(&io_args[0]);
                 }
                 2 => {
-                    args.input = io_args[0].clone();
-                    args.output = io_args[1].clone();
+                    args.input.clone_from(&io_args[0]);
+                    args.output.clone_from(&io_args[1]);
                 }
                 _ => Err(clap::Error::raw(
                     clap::error::ErrorKind::ValueValidation,
@@ -226,7 +226,7 @@ fn process_opts(mut opts: Opts) -> Result<Opts, clap::Error> {
             ))?;
         }
         if args.output.is_empty() {
-            args.output = std::path::Path::new(&args.input)
+            std::path::Path::new(&args.input)
                 .with_extension("tex")
                 .to_str()
                 .ok_or_else(|| {
@@ -235,7 +235,7 @@ fn process_opts(mut opts: Opts) -> Result<Opts, clap::Error> {
                         "Input file name is invalid.",
                     )
                 })?
-                .to_owned();
+                .clone_into(&mut args.output);
         }
     }
 
diff --git a/crates/mitex-lexer/src/snapshot_map.rs b/crates/mitex-lexer/src/snapshot_map.rs
index 0dc612f..748e604 100644
--- a/crates/mitex-lexer/src/snapshot_map.rs
+++ b/crates/mitex-lexer/src/snapshot_map.rs
@@ -93,10 +93,10 @@ where
         }
     }
 
-    pub fn get<Q: ?Sized>(&self, k: &Q) -> Option<&V>
+    pub fn get<Q>(&self, k: &Q) -> Option<&V>
     where
         K: Borrow<Q>,
-        Q: Hash + Eq,
+        Q: Hash + Eq + ?Sized,
     {
         self.map.borrow().get(k)
     }