diff --git a/src/book/book.rs b/src/book/book.rs
index c98c03c2..f4870f1f 100644
--- a/src/book/book.rs
+++ b/src/book/book.rs
@@ -82,7 +82,7 @@ impl Book {
     }
 
     /// Get a depth-first iterator over the items in the book.
-    pub fn iter(&self) -> BookItems {
+    pub fn iter(&self) -> BookItems<'_> {
         BookItems {
             items: self.sections.iter().collect(),
         }
@@ -286,7 +286,7 @@ impl<'a> Iterator for BookItems<'a> {
 }
 
 impl Display for Chapter {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         if let Some(ref section_number) = self.number {
             write!(f, "{} ", section_number)?;
         }
diff --git a/src/book/mod.rs b/src/book/mod.rs
index 41ae50d9..040e7265 100644
--- a/src/book/mod.rs
+++ b/src/book/mod.rs
@@ -37,10 +37,10 @@ pub struct MDBook {
     pub config: Config,
     /// A representation of the book's contents in memory.
     pub book: Book,
-    renderers: Vec<Box<Renderer>>,
+    renderers: Vec<Box<dyn Renderer>>,
 
     /// List of pre-processors to be run on the book
-    preprocessors: Vec<Box<Preprocessor>>,
+    preprocessors: Vec<Box<dyn Preprocessor>>,
 }
 
 impl MDBook {
@@ -146,7 +146,7 @@ impl MDBook {
     /// // etc.
     /// # }
     /// ```
-    pub fn iter(&self) -> BookItems {
+    pub fn iter(&self) -> BookItems<'_> {
         self.book.iter()
     }
 
@@ -183,7 +183,7 @@ impl MDBook {
     }
 
     /// Run the entire build process for a particular `Renderer`.
-    fn execute_build_process(&self, renderer: &Renderer) -> Result<()> {
+    fn execute_build_process(&self, renderer: &dyn Renderer) -> Result<()> {
         let mut preprocessed_book = self.book.clone();
         let preprocess_ctx = PreprocessorContext::new(
             self.root.clone(),
@@ -217,7 +217,7 @@ impl MDBook {
         Ok(())
     }
 
-    fn render(&self, preprocessed_book: &Book, renderer: &Renderer) -> Result<()> {
+    fn render(&self, preprocessed_book: &Book, renderer: &dyn Renderer) -> Result<()> {
         let name = renderer.name();
         let build_dir = self.build_dir_for(name);
 
@@ -344,8 +344,8 @@ impl MDBook {
 }
 
 /// Look at the `Config` and try to figure out what renderers to use.
-fn determine_renderers(config: &Config) -> Vec<Box<Renderer>> {
-    let mut renderers: Vec<Box<Renderer>> = Vec::new();
+fn determine_renderers(config: &Config) -> Vec<Box<dyn Renderer>> {
+    let mut renderers: Vec<Box<dyn Renderer>> = Vec::new();
 
     if let Some(output_table) = config.get("output").and_then(Value::as_table) {
         for (key, table) in output_table.iter() {
@@ -367,20 +367,20 @@ fn determine_renderers(config: &Config) -> Vec<Box<Renderer>> {
     renderers
 }
 
-fn default_preprocessors() -> Vec<Box<Preprocessor>> {
+fn default_preprocessors() -> Vec<Box<dyn Preprocessor>> {
     vec![
         Box::new(LinkPreprocessor::new()),
         Box::new(IndexPreprocessor::new()),
     ]
 }
 
-fn is_default_preprocessor(pre: &Preprocessor) -> bool {
+fn is_default_preprocessor(pre: &dyn Preprocessor) -> bool {
     let name = pre.name();
     name == LinkPreprocessor::NAME || name == IndexPreprocessor::NAME
 }
 
 /// Look at the `MDBook` and try to figure out what preprocessors to run.
-fn determine_preprocessors(config: &Config) -> Result<Vec<Box<Preprocessor>>> {
+fn determine_preprocessors(config: &Config) -> Result<Vec<Box<dyn Preprocessor>>> {
     let mut preprocessors = Vec::new();
 
     if config.build.use_default_preprocessors {
@@ -432,7 +432,11 @@ fn interpret_custom_renderer(key: &str, table: &Value) -> Box<CmdRenderer> {
 ///
 /// The `build.use-default-preprocessors` config option can be used to ensure
 /// default preprocessors always run if they support the renderer.
-fn preprocessor_should_run(preprocessor: &Preprocessor, renderer: &Renderer, cfg: &Config) -> bool {
+fn preprocessor_should_run(
+    preprocessor: &dyn Preprocessor,
+    renderer: &dyn Renderer,
+    cfg: &Config,
+) -> bool {
     // default preprocessors should be run by default (if supported)
     if cfg.build.use_default_preprocessors && is_default_preprocessor(preprocessor) {
         return preprocessor.supports_renderer(renderer.name());
diff --git a/src/book/summary.rs b/src/book/summary.rs
index d236d8a1..e61a3459 100644
--- a/src/book/summary.rs
+++ b/src/book/summary.rs
@@ -195,7 +195,7 @@ macro_rules! collect_events {
 }
 
 impl<'a> SummaryParser<'a> {
-    fn new(text: &str) -> SummaryParser {
+    fn new(text: &str) -> SummaryParser<'_> {
         let pulldown_parser = pulldown_cmark::Parser::new(text);
 
         SummaryParser {
@@ -471,7 +471,7 @@ fn get_last_link(links: &mut [SummaryItem]) -> Result<(usize, &mut Link)> {
 
 /// Removes the styling from a list of Markdown events and returns just the
 /// plain text.
-fn stringify_events(events: Vec<Event>) -> String {
+fn stringify_events(events: Vec<Event<'_>>) -> String {
     events
         .into_iter()
         .filter_map(|t| match t {
@@ -487,7 +487,7 @@ fn stringify_events(events: Vec<Event>) -> String {
 pub struct SectionNumber(pub Vec<u32>);
 
 impl Display for SectionNumber {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         if self.0.is_empty() {
             write!(f, "0")
         } else {
diff --git a/src/lib.rs b/src/lib.rs
index 7e350650..60f63e30 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -81,6 +81,7 @@
 //! [`Config`]: config/struct.Config.html
 
 #![deny(missing_docs)]
+#![deny(rust_2018_idioms)]
 
 #[macro_use]
 extern crate error_chain;
diff --git a/src/preprocess/links.rs b/src/preprocess/links.rs
index d852f706..f5a86905 100644
--- a/src/preprocess/links.rs
+++ b/src/preprocess/links.rs
@@ -294,7 +294,7 @@ impl<'a> Iterator for LinkIter<'a> {
     }
 }
 
-fn find_links(contents: &str) -> LinkIter {
+fn find_links(contents: &str) -> LinkIter<'_> {
     // lazily compute following regex
     // r"\\\{\{#.*\}\}|\{\{#([a-zA-Z0-9]+)\s*([a-zA-Z0-9_.\-:/\\\s]+)\}\}")?;
     lazy_static! {
diff --git a/src/renderer/html_handlebars/hbs_renderer.rs b/src/renderer/html_handlebars/hbs_renderer.rs
index 74358fb0..b77edc02 100644
--- a/src/renderer/html_handlebars/hbs_renderer.rs
+++ b/src/renderer/html_handlebars/hbs_renderer.rs
@@ -26,7 +26,7 @@ impl HtmlHandlebars {
     fn render_item(
         &self,
         item: &BookItem,
-        mut ctx: RenderItemContext,
+        mut ctx: RenderItemContext<'_>,
         print_content: &mut String,
     ) -> Result<()> {
         // FIXME: This should be made DRY-er and rely less on mutable state
@@ -505,7 +505,7 @@ fn build_header_links(html: &str) -> String {
     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");
@@ -552,7 +552,7 @@ fn wrap_header_with_link(
 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];
@@ -570,7 +570,7 @@ fn fix_code_blocks(html: &str) -> String {
 fn add_playpen_pre(html: &str, playpen_config: &Playpen) -> 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];
diff --git a/src/renderer/html_handlebars/helpers/navigation.rs b/src/renderer/html_handlebars/helpers/navigation.rs
index e62ae2f6..dd39400b 100644
--- a/src/renderer/html_handlebars/helpers/navigation.rs
+++ b/src/renderer/html_handlebars/helpers/navigation.rs
@@ -47,7 +47,7 @@ impl Target {
 
 fn find_chapter(
     ctx: &Context,
-    rc: &mut RenderContext,
+    rc: &mut RenderContext<'_>,
     target: Target,
 ) -> Result<Option<StringMap>, RenderError> {
     debug!("Get data from context");
@@ -86,11 +86,11 @@ fn find_chapter(
 }
 
 fn render(
-    _h: &Helper,
+    _h: &Helper<'_, '_>,
     r: &Handlebars,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_>,
+    out: &mut dyn Output,
     chapter: &StringMap,
 ) -> Result<(), RenderError> {
     trace!("Creating BTreeMap to inject in context");
@@ -137,11 +137,11 @@ fn render(
 }
 
 pub fn previous(
-    _h: &Helper,
+    _h: &Helper<'_, '_>,
     r: &Handlebars,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_>,
+    out: &mut dyn Output,
 ) -> Result<(), RenderError> {
     trace!("previous (handlebars helper)");
 
@@ -153,11 +153,11 @@ pub fn previous(
 }
 
 pub fn next(
-    _h: &Helper,
+    _h: &Helper<'_, '_>,
     r: &Handlebars,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_>,
+    out: &mut dyn Output,
 ) -> Result<(), RenderError> {
     trace!("next (handlebars helper)");
 
diff --git a/src/renderer/html_handlebars/helpers/theme.rs b/src/renderer/html_handlebars/helpers/theme.rs
index 44a4f85f..a42c2f91 100644
--- a/src/renderer/html_handlebars/helpers/theme.rs
+++ b/src/renderer/html_handlebars/helpers/theme.rs
@@ -1,11 +1,11 @@
 use handlebars::{Context, Handlebars, Helper, Output, RenderContext, RenderError};
 
 pub fn theme_option(
-    h: &Helper,
+    h: &Helper<'_, '_>,
     _r: &Handlebars,
     ctx: &Context,
-    rc: &mut RenderContext,
-    out: &mut Output,
+    rc: &mut RenderContext<'_>,
+    out: &mut dyn Output,
 ) -> Result<(), RenderError> {
     trace!("theme_option (handlebars helper)");
 
diff --git a/src/utils/mod.rs b/src/utils/mod.rs
index 7c7aeb51..8b113676 100644
--- a/src/utils/mod.rs
+++ b/src/utils/mod.rs
@@ -157,7 +157,7 @@ impl EventQuoteConverter {
     }
 }
 
-fn clean_codeblock_headers(event: Event) -> Event {
+fn clean_codeblock_headers(event: Event<'_>) -> Event<'_> {
     match event {
         Event::Start(Tag::CodeBlock(ref info)) => {
             let info: String = info.chars().filter(|ch| !ch.is_whitespace()).collect();