diff --git a/src/bin/mdbook.rs b/src/bin/mdbook.rs
index e48f8e66..1327a1f6 100644
--- a/src/bin/mdbook.rs
+++ b/src/bin/mdbook.rs
@@ -264,7 +264,7 @@ mod serve {
             None => book,
         };
 
-        if let None = book.get_destination() {
+        if book.get_destination().is_none() {
             println!("The HTML renderer is not set up, impossible to serve the files.");
             std::process::exit(2);
         }
diff --git a/src/book/mod.rs b/src/book/mod.rs
index e4a7ebd6..317ec043 100644
--- a/src/book/mod.rs
+++ b/src/book/mod.rs
@@ -247,7 +247,7 @@ impl MDBook {
             utils::fs::remove_dir_content(htmlconfig.get_destination())?;
         }
 
-        self.renderer.render(&self)
+        self.renderer.render(self)
     }
 
 
@@ -295,8 +295,7 @@ impl MDBook {
     }
 
     pub fn write_file<P: AsRef<Path>>(&self, filename: P, content: &[u8]) -> Result<()> {
-        let path = self.get_destination()
-            .ok_or(String::from("HtmlConfig not set, could not find a destination"))?
+        let path = self.get_destination().ok_or_else(|| String::from("HtmlConfig not set, could not find a destination"))?
             .join(filename);
 
         utils::fs::create_file(&path)?
diff --git a/src/config/jsonconfig.rs b/src/config/jsonconfig.rs
index 904787c0..5e553ee3 100644
--- a/src/config/jsonconfig.rs
+++ b/src/config/jsonconfig.rs
@@ -18,7 +18,7 @@ pub struct JsonConfig {
 }
 
 
-/// Returns a JsonConfig from a JSON string
+/// Returns a `JsonConfig` from a JSON string
 ///
 /// ```
 /// # use mdbook::config::jsonconfig::JsonConfig;
@@ -35,8 +35,8 @@ pub struct JsonConfig {
 impl JsonConfig {
     pub fn from_json(input: &str) -> Result<Self> {
         let config: JsonConfig = serde_json::from_str(input)
-                                        .chain_err(|| format!("Could not parse JSON"))?;
+                                        .chain_err(|| "Could not parse JSON")?;
 
-        return Ok(config);
+        Ok(config)
     }
 }
diff --git a/src/config/tomlconfig.rs b/src/config/tomlconfig.rs
index e75203aa..6a318097 100644
--- a/src/config/tomlconfig.rs
+++ b/src/config/tomlconfig.rs
@@ -31,7 +31,7 @@ pub struct TomlHtmlConfig {
     pub additional_js: Option<Vec<PathBuf>>,
 }
 
-/// Returns a TomlConfig from a TOML string
+/// Returns a `TomlConfig` from a TOML string
 ///
 /// ```
 /// # use mdbook::config::tomlconfig::TomlConfig;
@@ -49,7 +49,7 @@ impl TomlConfig {
         let config: TomlConfig = toml::from_str(input)
                                         .chain_err(|| "Could not parse TOML")?;
         
-        return Ok(config);
+        Ok(config)
     }
 }
 
diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 9c627553..604bba4d 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -77,7 +77,7 @@ impl HtmlHandlebars {
                     ctx.book.write_file(filename, &rendered.into_bytes())?;
 
                     if ctx.is_index {
-                        self.render_index(&ctx.book, ch, &ctx.destination)?;
+                        self.render_index(ctx.book, ch, &ctx.destination)?;
                     }
                 }
             },
@@ -121,10 +121,10 @@ impl HtmlHandlebars {
     }
 
     fn post_process(&self, rendered: String) -> String {
-        let rendered = build_header_links(rendered, "print.html");
-        let rendered = fix_anchor_links(rendered, "print.html");
-        let rendered = fix_code_blocks(rendered);
-        let rendered = add_playpen_pre(rendered);
+        let rendered = build_header_links(&rendered, "print.html");
+        let rendered = fix_anchor_links(&rendered, "print.html");
+        let rendered = fix_code_blocks(&rendered);
+        let rendered = add_playpen_pre(&rendered);
 
         rendered
     }
@@ -293,7 +293,7 @@ impl Renderer for HtmlHandlebars {
         self.copy_additional_css_and_js(book)?;
 
         // Copy all remaining files
-        utils::fs::copy_files_except_ext(book.get_source(), &destination, true, &["md"])?;
+        utils::fs::copy_files_except_ext(book.get_source(), destination, true, &["md"])?;
 
         Ok(())
     }
@@ -399,12 +399,12 @@ fn make_data(book: &MDBook) -> Result<serde_json::Map<String, serde_json::Value>
 
 /// Goes through the rendered HTML, making sure all header tags are wrapped in
 /// an anchor so people can link to sections directly.
-fn build_header_links(html: String, filename: &str) -> String {
+fn build_header_links(html: &str, filename: &str) -> String {
     let regex = Regex::new(r"<h(\d)>(.*?)</h\d>").unwrap();
     let mut id_counter = HashMap::new();
 
     regex
-        .replace_all(&html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures| {
             let level = caps[1].parse().expect(
                 "Regex should ensure we only ever get numbers here",
             );
@@ -477,10 +477,10 @@ fn id_from_content(content: &str) -> String {
 // anchors to the same page (href="#anchor") do not work because of
 // <base href="../"> pointing to the root folder. This function *fixes*
 // that in a very inelegant way
-fn fix_anchor_links(html: String, filename: &str) -> String {
+fn fix_anchor_links(html: &str, filename: &str) -> String {
     let regex = Regex::new(r##"<a([^>]+)href="#([^"]+)"([^>]*)>"##).unwrap();
     regex
-        .replace_all(&html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures| {
             let before = &caps[1];
             let anchor = &caps[2];
             let after = &caps[3];
@@ -505,10 +505,10 @@ fn fix_anchor_links(html: String, filename: &str) -> String {
 // }
 // ```
 // This function replaces all commas by spaces in the code block classes
-fn fix_code_blocks(html: String) -> String {
+fn fix_code_blocks(html: &str) -> String {
     let regex = Regex::new(r##"<code([^>]+)class="([^"]+)"([^>]*)>"##).unwrap();
     regex
-        .replace_all(&html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures| {
             let before = &caps[1];
             let classes = &caps[2].replace(",", " ");
             let after = &caps[3];
@@ -518,10 +518,10 @@ fn fix_code_blocks(html: String) -> String {
         .into_owned()
 }
 
-fn add_playpen_pre(html: String) -> String {
+fn add_playpen_pre(html: &str) -> String {
     let regex = Regex::new(r##"((?s)<code[^>]?class="([^"]+)".*?>(.*?)</code>)"##).unwrap();
     regex
-        .replace_all(&html, |caps: &Captures| {
+        .replace_all(html, |caps: &Captures| {
             let text = &caps[1];
             let classes = &caps[2];
             let code = &caps[3];
@@ -547,7 +547,7 @@ fn add_playpen_pre(html: String) -> String {
                 }
             } else {
                 // not language-rust, so no-op
-                format!("{}", text)
+                text.to_owned()
             }
         })
         .into_owned()
@@ -602,7 +602,7 @@ mod tests {
         ];
 
         for (src, should_be) in inputs {
-            let got = build_header_links(src.to_string(), "bar.rs");
+            let got = build_header_links(src, "bar.rs");
             assert_eq!(got, should_be);
         }
     }
diff --git a/src/renderer/html_handlebars/helpers/navigation.rs b/src/renderer/html_handlebars/helpers/navigation.rs
index a49db8b5..ef93e6c1 100644
--- a/src/renderer/html_handlebars/helpers/navigation.rs
+++ b/src/renderer/html_handlebars/helpers/navigation.rs
@@ -18,8 +18,7 @@ pub fn previous(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(
                   })?;
 
     let current = rc.evaluate_absolute("path")?
-        .as_str()
-        .ok_or(RenderError::new("Type error for `path`, string expected"))?
+        .as_str().ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
         .replace("\"", "");
 
     let mut previous: Option<BTreeMap<String, String>> = None;
@@ -41,8 +40,7 @@ pub fn previous(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(
 
                         // Chapter title
                         previous
-                            .get("name")
-                            .ok_or(RenderError::new("No title found for chapter in JSON data"))
+                            .get("name").ok_or_else(|| RenderError::new("No title found for chapter in JSON data"))
                             .and_then(|n| {
                                           previous_chapter.insert("title".to_owned(), json!(n));
                                           Ok(())
@@ -51,13 +49,11 @@ pub fn previous(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(
 
                         // Chapter link
                         previous
-                            .get("path")
-                            .ok_or(RenderError::new("No path found for chapter in JSON data"))
+                            .get("path").ok_or_else(|| RenderError::new("No path found for chapter in JSON data"))
                             .and_then(|p| {
                                 Path::new(p)
                                     .with_extension("html")
-                                    .to_str()
-                                    .ok_or(RenderError::new("Link could not be converted to str"))
+                                    .to_str().ok_or_else(|| RenderError::new("Link could not be converted to str"))
                                     .and_then(|p| {
                                                   previous_chapter
                                                       .insert("link".to_owned(), json!(p.replace("\\", "/")));
@@ -68,8 +64,7 @@ pub fn previous(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(
 
                         debug!("[*]: Render template");
                         // Render template
-                        _h.template()
-                            .ok_or(RenderError::new("Error with the handlebars template"))
+                        _h.template().ok_or_else(|| RenderError::new("Error with the handlebars template"))
                             .and_then(|t| {
                                           let mut local_rc = rc.with_context(Context::wraps(&previous_chapter));
                                           t.render(r, &mut local_rc)
@@ -101,8 +96,7 @@ pub fn next(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(), R
                           .map_err(|_| RenderError::new("Could not decode the JSON data"))
                   })?;
     let current = rc.evaluate_absolute("path")?
-        .as_str()
-        .ok_or(RenderError::new("Type error for `path`, string expected"))?
+        .as_str().ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
         .replace("\"", "");
 
     let mut previous: Option<BTreeMap<String, String>> = None;
@@ -118,8 +112,7 @@ pub fn next(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(), R
                 if let Some(previous) = previous {
 
                     let previous_path = previous
-                        .get("path")
-                        .ok_or(RenderError::new("No path found for chapter in JSON data"))?;
+                        .get("path").ok_or_else(|| RenderError::new("No path found for chapter in JSON data"))?;
 
                     if previous_path == &current {
 
@@ -128,8 +121,7 @@ pub fn next(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(), R
                         // Create new BTreeMap to extend the context: 'title' and 'link'
                         let mut next_chapter = BTreeMap::new();
 
-                        item.get("name")
-                            .ok_or(RenderError::new("No title found for chapter in JSON data"))
+                        item.get("name").ok_or_else(|| RenderError::new("No title found for chapter in JSON data"))
                             .and_then(|n| {
                                           next_chapter.insert("title".to_owned(), json!(n));
                                           Ok(())
@@ -137,8 +129,7 @@ pub fn next(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(), R
 
                         Path::new(path)
                             .with_extension("html")
-                            .to_str()
-                            .ok_or(RenderError::new("Link could not converted to str"))
+                            .to_str().ok_or_else(|| RenderError::new("Link could not converted to str"))
                             .and_then(|l| {
                                           debug!("[*]: Inserting link: {:?}", l);
                                           // Hack for windows who tends to use `\` as separator instead of `/`
@@ -149,8 +140,7 @@ pub fn next(_h: &Helper, r: &Handlebars, rc: &mut RenderContext) -> Result<(), R
                         debug!("[*]: Render template");
 
                         // Render template
-                        _h.template()
-                            .ok_or(RenderError::new("Error with the handlebars template"))
+                        _h.template().ok_or_else(|| RenderError::new("Error with the handlebars template"))
                             .and_then(|t| {
                                           let mut local_rc = rc.with_context(Context::wraps(&next_chapter));
                                           t.render(r, &mut local_rc)
diff --git a/src/renderer/html_handlebars/helpers/playpen.rs b/src/renderer/html_handlebars/helpers/playpen.rs
index d1fc28e7..6315cd99 100644
--- a/src/renderer/html_handlebars/helpers/playpen.rs
+++ b/src/renderer/html_handlebars/helpers/playpen.rs
@@ -36,11 +36,7 @@ pub fn render_playpen<P: AsRef<Path>>(s: &str, path: P) -> String {
             continue;
         };
 
-        let mut editable = "";
-        if playpen.editable {
-            editable = ",editable";
-        }
-
+        let editable = if playpen.editable { ",editable" } else { "" };
         let replacement = String::new() + "``` rust" + editable + "\n" + &file_content + "\n```\n";
 
         replaced.push_str(&s[previous_end_index..playpen.start_index]);
diff --git a/src/renderer/html_handlebars/helpers/toc.rs b/src/renderer/html_handlebars/helpers/toc.rs
index a007a8d3..c5f4b602 100644
--- a/src/renderer/html_handlebars/helpers/toc.rs
+++ b/src/renderer/html_handlebars/helpers/toc.rs
@@ -21,11 +21,10 @@ impl HelperDef for RenderToc {
                               .map_err(|_| RenderError::new("Could not decode the JSON data"))
                       })?;
         let current = rc.evaluate_absolute("path")?
-            .as_str()
-            .ok_or(RenderError::new("Type error for `path`, string expected"))?
+            .as_str().ok_or_else(|| RenderError::new("Type error for `path`, string expected"))?
             .replace("\"", "");
 
-        rc.writer.write_all("<ul class=\"chapter\">".as_bytes())?;
+        rc.writer.write_all(b"<ul class=\"chapter\">")?;
 
         let mut current_level = 1;
 
@@ -34,42 +33,42 @@ impl HelperDef for RenderToc {
             // Spacer
             if item.get("spacer").is_some() {
                 rc.writer
-                    .write_all("<li class=\"spacer\"></li>".as_bytes())?;
+                    .write_all(b"<li class=\"spacer\"></li>")?;
                 continue;
             }
 
             let level = if let Some(s) = item.get("section") {
-                s.matches(".").count()
+                s.matches('.').count()
             } else {
                 1
             };
 
             if level > current_level {
                 while level > current_level {
-                    rc.writer.write_all("<li>".as_bytes())?;
-                    rc.writer.write_all("<ul class=\"section\">".as_bytes())?;
+                    rc.writer.write_all(b"<li>")?;
+                    rc.writer.write_all(b"<ul class=\"section\">")?;
                     current_level += 1;
                 }
-                rc.writer.write_all("<li>".as_bytes())?;
+                rc.writer.write_all(b"<li>")?;
             } else if level < current_level {
                 while level < current_level {
-                    rc.writer.write_all("</ul>".as_bytes())?;
-                    rc.writer.write_all("</li>".as_bytes())?;
+                    rc.writer.write_all(b"</ul>")?;
+                    rc.writer.write_all(b"</li>")?;
                     current_level -= 1;
                 }
-                rc.writer.write_all("<li>".as_bytes())?;
+                rc.writer.write_all(b"<li>")?;
             } else {
-                rc.writer.write_all("<li".as_bytes())?;
+                rc.writer.write_all(b"<li")?;
                 if item.get("section").is_none() {
-                    rc.writer.write_all(" class=\"affix\"".as_bytes())?;
+                    rc.writer.write_all(b" class=\"affix\"")?;
                 }
-                rc.writer.write_all(">".as_bytes())?;
+                rc.writer.write_all(b">")?;
             }
 
             // Link
             let path_exists = if let Some(path) = item.get("path") {
                 if !path.is_empty() {
-                    rc.writer.write_all("<a href=\"".as_bytes())?;
+                    rc.writer.write_all(b"<a href=\"")?;
 
                     let tmp = Path::new(item.get("path").expect("Error: path should be Some(_)"))
                         .with_extension("html")
@@ -80,13 +79,13 @@ impl HelperDef for RenderToc {
 
                     // Add link
                     rc.writer.write_all(tmp.as_bytes())?;
-                    rc.writer.write_all("\"".as_bytes())?;
+                    rc.writer.write_all(b"\"")?;
 
                     if path == &current {
-                        rc.writer.write_all(" class=\"active\"".as_bytes())?;
+                        rc.writer.write_all(b" class=\"active\"")?;
                     }
 
-                    rc.writer.write_all(">".as_bytes())?;
+                    rc.writer.write_all(b">")?;
                     true
                 } else {
                     false
@@ -97,9 +96,9 @@ impl HelperDef for RenderToc {
 
             // Section does not necessarily exist
             if let Some(section) = item.get("section") {
-                rc.writer.write_all("<strong>".as_bytes())?;
+                rc.writer.write_all(b"<strong>")?;
                 rc.writer.write_all(section.as_bytes())?;
-                rc.writer.write_all("</strong> ".as_bytes())?;
+                rc.writer.write_all(b"</strong> ")?;
             }
 
             if let Some(name) = item.get("name") {
@@ -123,19 +122,19 @@ impl HelperDef for RenderToc {
             }
 
             if path_exists {
-                rc.writer.write_all("</a>".as_bytes())?;
+                rc.writer.write_all(b"</a>")?;
             }
 
-            rc.writer.write_all("</li>".as_bytes())?;
+            rc.writer.write_all(b"</li>")?;
 
         }
         while current_level > 1 {
-            rc.writer.write_all("</ul>".as_bytes())?;
-            rc.writer.write_all("</li>".as_bytes())?;
+            rc.writer.write_all(b"</ul>")?;
+            rc.writer.write_all(b"</li>")?;
             current_level -= 1;
         }
 
-        rc.writer.write_all("</ul>".as_bytes())?;
+        rc.writer.write_all(b"</ul>")?;
         Ok(())
     }
 }
diff --git a/tests/jsonconfig.rs b/tests/jsonconfig.rs
index 43b4680f..003f1bc4 100644
--- a/tests/jsonconfig.rs
+++ b/tests/jsonconfig.rs
@@ -11,7 +11,7 @@ fn from_json_source() {
         "src": "source"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     assert_eq!(config.get_source(), PathBuf::from("root/source"));
@@ -24,7 +24,7 @@ fn from_json_title() {
         "title": "Some title"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     assert_eq!(config.get_title(), "Some title");
@@ -37,7 +37,7 @@ fn from_json_description() {
         "description": "This is a description"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     assert_eq!(config.get_description(), "This is a description");
@@ -50,7 +50,7 @@ fn from_json_author() {
         "author": "John Doe"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     assert_eq!(config.get_authors(), &[String::from("John Doe")]);
@@ -63,7 +63,7 @@ fn from_json_destination() {
         "dest": "htmlbook"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -78,7 +78,7 @@ fn from_json_output_html_theme() {
         "theme_path": "theme"
     }"#;
 
-    let parsed = JsonConfig::from_json(&json).expect("This should parse");
+    let parsed = JsonConfig::from_json(json).expect("This should parse");
     let config = BookConfig::from_jsonconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
diff --git a/tests/tomlconfig.rs b/tests/tomlconfig.rs
index a751b359..5ce23944 100644
--- a/tests/tomlconfig.rs
+++ b/tests/tomlconfig.rs
@@ -9,7 +9,7 @@ use std::path::PathBuf;
 fn from_toml_source() {
     let toml = r#"source = "source""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     assert_eq!(config.get_source(), PathBuf::from("root/source"));
@@ -20,7 +20,7 @@ fn from_toml_source() {
 fn from_toml_title() {
     let toml = r#"title = "Some title""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     assert_eq!(config.get_title(), "Some title");
@@ -31,7 +31,7 @@ fn from_toml_title() {
 fn from_toml_description() {
     let toml = r#"description = "This is a description""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     assert_eq!(config.get_description(), "This is a description");
@@ -42,7 +42,7 @@ fn from_toml_description() {
 fn from_toml_author() {
     let toml = r#"author = "John Doe""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     assert_eq!(config.get_authors(), &[String::from("John Doe")]);
@@ -53,7 +53,7 @@ fn from_toml_author() {
 fn from_toml_authors() {
     let toml = r#"authors = ["John Doe", "Jane Doe"]"#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     assert_eq!(config.get_authors(), &[String::from("John Doe"), String::from("Jane Doe")]);
@@ -65,7 +65,7 @@ fn from_toml_output_html_destination() {
     let toml = r#"[output.html]
     destination = "htmlbook""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -79,7 +79,7 @@ fn from_toml_output_html_theme() {
     let toml = r#"[output.html]
     theme = "theme""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -93,7 +93,7 @@ fn from_toml_output_html_curly_quotes() {
     let toml = r#"[output.html]
     curly-quotes = true"#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -107,7 +107,7 @@ fn from_toml_output_html_mathjax_support() {
     let toml = r#"[output.html]
     mathjax-support = true"#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -121,7 +121,7 @@ fn from_toml_output_html_google_analytics() {
     let toml = r#"[output.html]
     google-analytics = "123456""#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -135,7 +135,7 @@ fn from_toml_output_html_additional_stylesheet() {
     let toml = r#"[output.html]
     additional-css = ["custom.css", "two/custom.css"]"#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");
@@ -149,7 +149,7 @@ fn from_toml_output_html_additional_scripts() {
     let toml = r#"[output.html]
     additional-js = ["custom.js", "two/custom.js"]"#;
 
-    let parsed = TomlConfig::from_toml(&toml).expect("This should parse");
+    let parsed = TomlConfig::from_toml(toml).expect("This should parse");
     let config = BookConfig::from_tomlconfig("root", parsed);
 
     let htmlconfig = config.get_html_config().expect("There should be an HtmlConfig");