diff --git a/website/doc/src/for_developers/preprocessors.md b/website/doc/src/for_developers/preprocessors.md
index 1ac46256..dbe78779 100644
--- a/website/doc/src/for_developers/preprocessors.md
+++ b/website/doc/src/for_developers/preprocessors.md
@@ -33,14 +33,6 @@ translates inputs to the correct `Preprocessor` method. For convenience, there
 is [an example no-op preprocessor] in the `examples/` directory which can easily
 be adapted for other preprocessors.
 
-<details>
-<summary>Example no-op preprocessor</summary>
-
-```rust
-// nop-preprocessors.rs
-
-{{#include ../../../examples/nop-preprocessor.rs}}
-```
 </details>
 
 ## Hints For Implementing A Preprocessor
diff --git a/website/examples/nop-preprocessor.rs b/website/examples/nop-preprocessor.rs
deleted file mode 100644
index ace40093..00000000
--- a/website/examples/nop-preprocessor.rs
+++ /dev/null
@@ -1,104 +0,0 @@
-use crate::nop_lib::Nop;
-use clap::{App, Arg, ArgMatches};
-use mdbook::book::Book;
-use mdbook::errors::Error;
-use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext};
-use semver::{Version, VersionReq};
-use std::io;
-use std::process;
-
-pub fn make_app() -> App<'static> {
-    App::new("nop-preprocessor")
-        .about("A mdbook preprocessor which does precisely nothing")
-        .subcommand(
-            App::new("supports")
-                .arg(Arg::new("renderer").required(true))
-                .about("Check whether a renderer is supported by this preprocessor"),
-        )
-}
-
-fn main() {
-    let matches = make_app().get_matches();
-
-    // Users will want to construct their own preprocessor here
-    let preprocessor = Nop::new();
-
-    if let Some(sub_args) = matches.subcommand_matches("supports") {
-        handle_supports(&preprocessor, sub_args);
-    } else if let Err(e) = handle_preprocessing(&preprocessor) {
-        eprintln!("{}", e);
-        process::exit(1);
-    }
-}
-
-fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
-    let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?;
-
-    let book_version = Version::parse(&ctx.mdbook_version)?;
-    let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?;
-
-    if !version_req.matches(&book_version) {
-        eprintln!(
-            "Warning: The {} plugin was built against version {} of mdbook, \
-             but we're being called from version {}",
-            pre.name(),
-            mdbook::MDBOOK_VERSION,
-            ctx.mdbook_version
-        );
-    }
-
-    let processed_book = pre.run(&ctx, book)?;
-    serde_json::to_writer(io::stdout(), &processed_book)?;
-
-    Ok(())
-}
-
-fn handle_supports(pre: &dyn Preprocessor, sub_args: &ArgMatches) -> ! {
-    let renderer = sub_args.value_of("renderer").expect("Required argument");
-    let supported = pre.supports_renderer(renderer);
-
-    // Signal whether the renderer is supported by exiting with 1 or 0.
-    if supported {
-        process::exit(0);
-    } else {
-        process::exit(1);
-    }
-}
-
-/// The actual implementation of the `Nop` preprocessor. This would usually go
-/// in your main `lib.rs` file.
-mod nop_lib {
-    use super::*;
-
-    /// A no-op preprocessor.
-    pub struct Nop;
-
-    impl Nop {
-        pub fn new() -> Nop {
-            Nop
-        }
-    }
-
-    impl Preprocessor for Nop {
-        fn name(&self) -> &str {
-            "nop-preprocessor"
-        }
-
-        fn run(&self, ctx: &PreprocessorContext, book: Book) -> Result<Book, Error> {
-            // In testing we want to tell the preprocessor to blow up by setting a
-            // particular config value
-            if let Some(nop_cfg) = ctx.config.get_preprocessor(self.name()) {
-                if nop_cfg.contains_key("blow-up") {
-                    anyhow::bail!("Boom!!1!");
-                }
-            }
-
-            // we *are* a no-op preprocessor after all
-            Ok(book)
-        }
-
-        fn supports_renderer(&self, renderer: &str) -> bool {
-            renderer != "not-supported"
-        }
-    }
-}