diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d2ef967a..c78ae786 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -107,7 +107,7 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: clippy
-          args: -- -D warnings --allow clippy::needless_borrow
+          args: -- -D warnings
 
   coverage:
     name: Code coverage
diff --git a/src/color.rs b/src/color.rs
index 10d9cafd..8b7428be 100644
--- a/src/color.rs
+++ b/src/color.rs
@@ -90,7 +90,7 @@ pub fn ansi_16_color_name_to_number(name: &str) -> Option<u8> {
 fn ansi_16_color_number_to_name(n: u8) -> Option<&'static str> {
     for (k, _n) in &*ANSI_16_COLORS {
         if *_n == n {
-            return Some(&*k);
+            return Some(*k);
         }
     }
     None
diff --git a/src/delta.rs b/src/delta.rs
index bc691748..e1770b7e 100644
--- a/src/delta.rs
+++ b/src/delta.rs
@@ -112,7 +112,7 @@ impl<'a> StateMachine<'a> {
             let line = &self.line;
 
             if self.source == Source::Unknown {
-                self.source = detect_source(&line);
+                self.source = detect_source(line);
             }
 
             let mut handled_line = if self.config.commit_regex.is_match(line) {
@@ -174,7 +174,7 @@ impl<'a> StateMachine<'a> {
 
     fn ingest_line(&mut self, raw_line_bytes: &[u8]) {
         // TODO: retain raw_line as Cow
-        self.raw_line = String::from_utf8_lossy(&raw_line_bytes).to_string();
+        self.raw_line = String::from_utf8_lossy(raw_line_bytes).to_string();
         if self.config.max_line_length > 0 && self.raw_line.len() > self.config.max_line_length {
             self.raw_line = ansi::truncate_str(
                 &self.raw_line,
diff --git a/src/features/side_by_side.rs b/src/features/side_by_side.rs
index abb1a16d..77f48933 100644
--- a/src/features/side_by_side.rs
+++ b/src/features/side_by_side.rs
@@ -190,8 +190,8 @@ fn paint_left_panel_minus_line<'a>(
 ) -> String {
     let (mut panel_line, panel_line_is_empty) = paint_minus_or_plus_panel_line(
         line_index,
-        &syntax_style_sections,
-        &diff_style_sections,
+        syntax_style_sections,
+        diff_style_sections,
         state,
         line_numbers_data,
         PanelSide::Left,
@@ -224,8 +224,8 @@ fn paint_right_panel_plus_line<'a>(
 ) -> String {
     let (mut panel_line, panel_line_is_empty) = paint_minus_or_plus_panel_line(
         line_index,
-        &syntax_style_sections,
-        &diff_style_sections,
+        syntax_style_sections,
+        diff_style_sections,
         state,
         line_numbers_data,
         PanelSide::Right,
@@ -384,13 +384,13 @@ fn right_pad_left_panel_line(
         };
     };
     // Pad with (maybe painted) spaces to the panel width.
-    let text_width = ansi::measure_text_width(&panel_line);
+    let text_width = ansi::measure_text_width(panel_line);
     let panel_width = config.side_by_side_data.left_panel.width;
     if text_width < panel_width {
         let fill_style = get_right_fill_style_for_left_panel(
             panel_line_is_empty,
             line_index,
-            &diff_style_sections,
+            diff_style_sections,
             state,
             background_color_extends_to_terminal_width,
             config,
@@ -420,7 +420,7 @@ fn right_fill_right_panel_line(
     config: &Config,
 ) {
     *panel_line = ansi::truncate_str(
-        &panel_line,
+        panel_line,
         config.side_by_side_data.right_panel.width,
         &config.truncation_symbol,
     )
diff --git a/src/hunk_header.rs b/src/hunk_header.rs
index b72c1650..0889f41f 100644
--- a/src/hunk_header.rs
+++ b/src/hunk_header.rs
@@ -148,7 +148,7 @@ fn write_to_output_buffer(
             &lines,
             &delta::State::HunkHeader,
             &mut painter.highlighter,
-            &painter.config,
+            painter.config,
         );
         Painter::paint_lines(
             syntax_style_sections,
diff --git a/src/main.rs b/src/main.rs
index a36ee795..1b77808f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -173,7 +173,7 @@ You can also use delta to diff two files: `delta file_A file_B`."
     if let Err(error) = delta(
         BufReader::new(diff_process.stdout.unwrap()).byte_lines(),
         writer,
-        &config,
+        config,
     ) {
         match error.kind() {
             ErrorKind::BrokenPipe => return 0,
@@ -363,7 +363,7 @@ fn show_themes(dark: bool, light: bool, computed_theme_is_light: bool) -> std::i
 
     for theme in &get_themes(git_config::GitConfig::try_create()) {
         let opt =
-            cli::Opt::from_iter_and_git_config(&["", "", "--features", &theme], &mut git_config);
+            cli::Opt::from_iter_and_git_config(&["", "", "--features", theme], &mut git_config);
         let is_dark_theme = opt.dark;
         let is_light_theme = opt.light;
         let config = config::Config::from(opt);
diff --git a/src/options/get.rs b/src/options/get.rs
index 6026fb50..2d05f5ac 100644
--- a/src/options/get.rs
+++ b/src/options/get.rs
@@ -82,8 +82,8 @@ pub trait GetOptionValue {
         for feature in opt.features.to_lowercase().split_whitespace().rev() {
             match Self::get_provenanced_value_for_feature(
                 option_name,
-                &feature,
-                &builtin_features,
+                feature,
+                builtin_features,
                 opt,
                 git_config,
             ) {
@@ -120,7 +120,7 @@ pub trait GetOptionValue {
         }
         if let Some(builtin_feature) = builtin_features.get(feature) {
             if let Some(value_function) = builtin_feature.get(option_name) {
-                return Some(value_function(opt, &git_config));
+                return Some(value_function(opt, git_config));
             }
         }
         None
diff --git a/src/options/set.rs b/src/options/set.rs
index 063c999c..42a98387 100644
--- a/src/options/set.rs
+++ b/src/options/set.rs
@@ -221,7 +221,7 @@ fn set__light__dark__syntax_theme__options(
         }
     };
     let empty_builtin_features = HashMap::new();
-    validate_light_and_dark(&opt);
+    validate_light_and_dark(opt);
     if !(opt.light || opt.dark) {
         set_options!(
             [dark, light],
@@ -233,7 +233,7 @@ fn set__light__dark__syntax_theme__options(
             false
         );
     }
-    validate_light_and_dark(&opt);
+    validate_light_and_dark(opt);
     set_options!(
         [syntax_theme],
         opt,
@@ -304,7 +304,7 @@ fn gather_features(
     // Gather features from command line.
     if let Some(git_config) = git_config {
         for feature in split_feature_string(&opt.features.to_lowercase()) {
-            gather_features_recursively(feature, &mut features, &builtin_features, opt, git_config);
+            gather_features_recursively(feature, &mut features, builtin_features, opt, git_config);
         }
     } else {
         for feature in split_feature_string(&opt.features.to_lowercase()) {
@@ -315,33 +315,28 @@ fn gather_features(
     // Gather builtin feature flags supplied on command line.
     // TODO: Iterate over programatically-obtained names of builtin features.
     if opt.raw {
-        gather_builtin_features_recursively("raw", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("raw", &mut features, builtin_features, opt);
     }
     if opt.color_only {
-        gather_builtin_features_recursively("color-only", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("color-only", &mut features, builtin_features, opt);
     }
     if opt.diff_highlight {
-        gather_builtin_features_recursively(
-            "diff-highlight",
-            &mut features,
-            &builtin_features,
-            opt,
-        );
+        gather_builtin_features_recursively("diff-highlight", &mut features, builtin_features, opt);
     }
     if opt.diff_so_fancy {
-        gather_builtin_features_recursively("diff-so-fancy", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("diff-so-fancy", &mut features, builtin_features, opt);
     }
     if opt.hyperlinks {
-        gather_builtin_features_recursively("hyperlinks", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("hyperlinks", &mut features, builtin_features, opt);
     }
     if opt.line_numbers {
-        gather_builtin_features_recursively("line-numbers", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("line-numbers", &mut features, builtin_features, opt);
     }
     if opt.navigate {
-        gather_builtin_features_recursively("navigate", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("navigate", &mut features, builtin_features, opt);
     }
     if opt.side_by_side {
-        gather_builtin_features_recursively("side-by-side", &mut features, &builtin_features, opt);
+        gather_builtin_features_recursively("side-by-side", &mut features, builtin_features, opt);
     }
 
     if let Some(git_config) = git_config {
@@ -352,7 +347,7 @@ fn gather_features(
                     gather_features_recursively(
                         feature,
                         &mut features,
-                        &builtin_features,
+                        builtin_features,
                         opt,
                         git_config,
                     )
@@ -363,7 +358,7 @@ fn gather_features(
         gather_builtin_features_from_flags_in_gitconfig(
             "delta",
             &mut features,
-            &builtin_features,
+            builtin_features,
             opt,
             git_config,
         );
diff --git a/src/paint.rs b/src/paint.rs
index 916276f1..3b5010b2 100644
--- a/src/paint.rs
+++ b/src/paint.rs
@@ -69,7 +69,7 @@ impl<'a> Painter<'a> {
 
     pub fn set_highlighter(&mut self) {
         if let Some(ref syntax_theme) = self.config.syntax_theme {
-            self.highlighter = HighlightLines::new(self.syntax, &syntax_theme)
+            self.highlighter = HighlightLines::new(self.syntax, syntax_theme)
         };
     }
 
@@ -205,7 +205,7 @@ impl<'a> Painter<'a> {
             &lines,
             &state,
             &mut self.highlighter,
-            &self.config,
+            self.config,
         );
         let diff_style_sections = vec![(self.config.zero_style, lines[0].0.as_str())]; // TODO: compute style from state
 
@@ -496,11 +496,11 @@ impl<'a> Painter<'a> {
     ) {
         let (minus_lines, minus_styles): (Vec<&str>, Vec<Style>) = minus_lines
             .iter()
-            .map(|(s, t)| (s.as_str(), *config.get_style(&t)))
+            .map(|(s, t)| (s.as_str(), *config.get_style(t)))
             .unzip();
         let (plus_lines, plus_styles): (Vec<&str>, Vec<Style>) = plus_lines
             .iter()
-            .map(|(s, t)| (s.as_str(), *config.get_style(&t)))
+            .map(|(s, t)| (s.as_str(), *config.get_style(t)))
             .unzip();
         let mut diff_sections = edits::infer_edits(
             minus_lines,
diff --git a/src/parse.rs b/src/parse.rs
index b39da14f..a62d486c 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -102,7 +102,7 @@ fn _parse_file_path(s: &str, git_diff_name: bool) -> String {
     match s.strip_suffix('\t').unwrap_or(s) {
         path if path == "/dev/null" => "/dev/null",
         path if git_diff_name && DIFF_PREFIXES.iter().any(|s| path.starts_with(s)) => &path[2..],
-        path if git_diff_name => &path,
+        path if git_diff_name => path,
         path => path.split('\t').next().unwrap_or(""),
     }
     .to_string()
@@ -142,7 +142,7 @@ pub fn get_file_extension_from_file_meta_line_file_path(path: &str) -> Option<&s
     if path.is_empty() || path == "/dev/null" {
         None
     } else {
-        get_extension(&path).map(|ex| ex.trim())
+        get_extension(path).map(|ex| ex.trim())
     }
 }
 
diff --git a/src/parse_style.rs b/src/parse_style.rs
index 02c455b0..18ba4b28 100644
--- a/src/parse_style.rs
+++ b/src/parse_style.rs
@@ -19,7 +19,7 @@ impl Style {
         is_emph: bool,
     ) -> Self {
         let (ansi_term_style, is_omitted, is_raw, is_syntax_highlighted) =
-            parse_ansi_term_style(&style_string, default, true_color);
+            parse_ansi_term_style(style_string, default, true_color);
         let decoration_style =
             DecorationStyle::from_str(decoration_style_string.unwrap_or(""), true_color);
         Self {
@@ -132,7 +132,7 @@ bitflags! {
 impl DecorationStyle {
     pub fn from_str(style_string: &str, true_color: bool) -> Self {
         let (special_attributes, style_string) =
-            extract_special_decoration_attributes(&style_string);
+            extract_special_decoration_attributes(style_string);
         let (style, is_omitted, is_raw, is_syntax_highlighted) =
             parse_ansi_term_style(&style_string, None, true_color);
         if is_raw {