diff --git a/crates/mdbook-driver/src/builtin_renderers/mod.rs b/crates/mdbook-driver/src/builtin_renderers/mod.rs
index 6ac1ee24bb..980c0a6f2d 100644
--- a/crates/mdbook-driver/src/builtin_renderers/mod.rs
+++ b/crates/mdbook-driver/src/builtin_renderers/mod.rs
@@ -50,7 +50,7 @@ impl CmdRenderer {
         CmdRenderer { name, cmd }
     }
 
-    fn compose_command(&self, root: &Path, destination: &Path) -> Result<Command> {
+    fn compose_command(&self, root: &Path) -> Result<Command> {
         let mut words = Shlex::new(&self.cmd);
         let exe = match words.next() {
             Some(e) => PathBuf::from(e),
@@ -61,30 +61,8 @@ impl CmdRenderer {
             // Search PATH for the executable.
             exe
         } else {
-            // Relative paths are preferred to be relative to the book root.
-            let abs_exe = root.join(&exe);
-            if abs_exe.exists() {
-                abs_exe
-            } else {
-                // Historically paths were relative to the destination, but
-                // this is not the preferred way.
-                let legacy_path = destination.join(&exe);
-                if legacy_path.exists() {
-                    warn!(
-                        "Renderer command `{}` uses a path relative to the \
-                        renderer output directory `{}`. This was previously \
-                        accepted, but has been deprecated. Relative executable \
-                        paths should be relative to the book root.",
-                        exe.display(),
-                        destination.display()
-                    );
-                    legacy_path
-                } else {
-                    // Let this bubble through to later be handled by
-                    // handle_render_command_error.
-                    abs_exe
-                }
-            }
+            // Relative path is relative to book root.
+            root.join(&exe)
         };
 
         let mut cmd = Command::new(exe);
@@ -143,7 +121,7 @@ impl Renderer for CmdRenderer {
         let _ = fs::create_dir_all(&ctx.destination);
 
         let mut child = match self
-            .compose_command(&ctx.root, &ctx.destination)?
+            .compose_command(&ctx.root)?
             .stdin(Stdio::piped())
             .stdout(Stdio::inherit())
             .stderr(Stdio::inherit())
diff --git a/tests/testsuite/renderer.rs b/tests/testsuite/renderer.rs
index da89dbcc53..28ff25be46 100644
--- a/tests/testsuite/renderer.rs
+++ b/tests/testsuite/renderer.rs
@@ -211,11 +211,10 @@ fn backends_receive_render_context_via_stdin() {
     RenderContext::from_json(f).unwrap();
 }
 
-// Legacy relative renderer paths.
-//
-// https://github.com/rust-lang/mdBook/pull/1418
+// Verifies that a relative path for the renderer command is relative to the
+// book root.
 #[test]
-fn legacy_relative_command_path() {
+fn relative_command_path() {
     let mut test = BookTest::init(|_| {});
     test.rust_program(
         "renderers/myrenderer",
@@ -228,7 +227,6 @@ fn legacy_relative_command_path() {
         }
         "#,
     )
-    // Test with a modern path, relative to the book directory.
     .change_file(
         "book.toml",
         "[output.myrenderer]\n\
@@ -240,26 +238,6 @@ fn legacy_relative_command_path() {
 [TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the myrenderer backend
 [TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "myrenderer" renderer
 
-"#]]);
-    })
-    .check_file("book/output", "test");
-    std::fs::remove_file(test.dir.join("book/output")).unwrap();
-    // Test with legacy path, relative to the output directory.
-    test.change_file(
-        "book.toml",
-        &format!(
-            "[output.myrenderer]\n\
-             command = '../renderers/myrenderer{exe}'\n",
-            exe = std::env::consts::EXE_SUFFIX
-        ),
-    )
-    .run("build", |cmd| {
-        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the myrenderer backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "myrenderer" renderer
-[TIMESTAMP] [WARN] (mdbook_driver::builtin_renderers): Renderer command `../renderers/myrenderer[EXE]` uses a path relative to the renderer output directory `[ROOT]/book`. This was previously accepted, but has been deprecated. Relative executable paths should be relative to the book root.
-
 "#]]);
     })
     .check_file("book/output", "test");