diff --git a/src/input.rs b/src/input.rs
index 90e7dd6..3283d35 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -79,7 +79,7 @@ pub fn convert_key(ev: &EventKey) -> Option<String> {
 
 pub fn im_input(nvim: &mut Neovim, input: &str) {
     debug!("nvim_input -> {}", input);
-    nvim.input(&input).expect("Error run input command to nvim");
+    nvim.input(input).expect("Error run input command to nvim");
 }
 
 pub fn gtk_key_press(nvim: &mut Neovim, ev: &EventKey) -> Inhibit {
diff --git a/src/main.rs b/src/main.rs
index 1216c48..e2cf6c1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -20,7 +20,6 @@ extern crate htmlescape;
 
 #[macro_use]
 extern crate serde_derive;
-extern crate serde;
 extern crate toml;
 
 mod sys;
diff --git a/src/project.rs b/src/project.rs
index d825951..deeaf4a 100644
--- a/src/project.rs
+++ b/src/project.rs
@@ -182,8 +182,8 @@ impl Projects {
             let uri_value = list_store.get_value(&iter, ProjectViewColumns::Uri as i32);
             let uri: String = uri_value.get().unwrap();
 
-            let mut store = self.store.as_mut().unwrap();
-            if let Some(mut entry) = store.find_mut(&uri) {
+            let store = self.store.as_mut().unwrap();
+            if let Some(entry) = store.find_mut(&uri) {
                 entry.stored = !value;
             }
 
diff --git a/src/render/mod.rs b/src/render/mod.rs
index 73218a6..6a25868 100644
--- a/src/render/mod.rs
+++ b/src/render/mod.rs
@@ -127,7 +127,7 @@ pub fn shape_dirty(
 
             for i in 0..line.line.len() {
                 if line[i].dirty {
-                    if let Some(mut item) = line.get_item_mut(i) {
+                    if let Some(item) = line.get_item_mut(i) {
                         let mut glyphs = pango::GlyphString::new();
                         {
                             let analysis = item.analysis();
diff --git a/src/shell.rs b/src/shell.rs
index f7391e3..ec6e2ad 100644
--- a/src/shell.rs
+++ b/src/shell.rs
@@ -462,7 +462,7 @@ impl Shell {
 
     pub fn edit_save_all(&self) {
         let state = self.state.borrow();
-        let mut nvim = &mut *state.nvim();
+        let nvim = &mut *state.nvim();
         nvim.command(":wa").report_err(nvim);
     }
 
@@ -591,7 +591,7 @@ fn gtk_draw(state_arc: &Arc<UiMutex<State>>, ctx: &cairo::Context) -> Inhibit {
     Inhibit(false)
 }
 
-fn show_nvim_start_error(err: nvim::NvimInitError, state_arc: Arc<UiMutex<State>>) {
+fn show_nvim_start_error(err: &nvim::NvimInitError, state_arc: Arc<UiMutex<State>>) {
     let source = err.source();
     let cmd = err.cmd().unwrap().to_owned();
 
@@ -605,7 +605,7 @@ fn show_nvim_start_error(err: nvim::NvimInitError, state_arc: Arc<UiMutex<State>
     });
 }
 
-fn show_nvim_init_error(err: nvim::NvimInitError, state_arc: Arc<UiMutex<State>>) {
+fn show_nvim_init_error(err: &nvim::NvimInitError, state_arc: Arc<UiMutex<State>>) {
     let source = err.source();
 
     glib::idle_add(move || {
@@ -628,7 +628,7 @@ fn init_nvim_async(
     let mut nvim = match nvim::start(state_arc.clone(), options.nvim_bin_path.as_ref()) {
         Ok(nvim) => nvim,
         Err(err) => {
-            show_nvim_start_error(err, state_arc);
+            show_nvim_start_error(&err, state_arc);
             return;
         }
     };
@@ -653,7 +653,7 @@ fn init_nvim_async(
             rows as u64,
         )
         {
-            show_nvim_init_error(err, state_arc.clone());
+            show_nvim_init_error(&err, state_arc.clone());
         } else {
             let mut state = state_arc.borrow_mut();
             state.nvim.borrow_mut().set_initialized(nvim);
diff --git a/src/ui_model/line.rs b/src/ui_model/line.rs
index 29841e9..ba52ef7 100644
--- a/src/ui_model/line.rs
+++ b/src/ui_model/line.rs
@@ -93,8 +93,7 @@ impl Line {
             // update only if cell marked as dirty
             if self.line[new_item.start_cell..new_item.end_cell + 1]
                 .iter()
-                .find(|c| c.dirty)
-                .is_some()
+                .any(|c| c.dirty)
             {
                 self.item_line[new_item.start_cell]
                     .as_mut()
diff --git a/src/ui_model/mod.rs b/src/ui_model/mod.rs
index 98d2822..006f3bc 100644
--- a/src/ui_model/mod.rs
+++ b/src/ui_model/mod.rs
@@ -72,11 +72,11 @@ impl UiModel {
 
     pub fn put(&mut self, text: &str, attrs: Option<&Attrs>) -> ModelRect {
         let mut changed_region = self.cur_point();
-        let mut line = &mut self.model[self.cur_row];
+        let line = &mut self.model[self.cur_row];
         line.dirty_line = true;
         line.mark_dirty_cell(self.cur_col);
 
-        let mut cell = &mut line[self.cur_col];
+        let cell = &mut line[self.cur_col];
 
         cell.ch = text.chars().last().unwrap_or(' ');
         cell.attrs = attrs.map(Attrs::clone).unwrap_or_else(Attrs::new);
@@ -100,7 +100,7 @@ impl UiModel {
 
     #[inline]
     fn copy_row(&mut self, target_row: i64, offset: i64, left_col: usize, right_col: usize) {
-        debug_assert!(offset != 0);
+        debug_assert_ne!(0, offset);
 
         let from_row = (target_row + offset) as usize;