diff --git a/xtask/src/doc.rs b/xtask/src/doc.rs
new file mode 100644
index 00000000..d513c0bb
--- /dev/null
+++ b/xtask/src/doc.rs
@@ -0,0 +1,41 @@
+use clap::Args;
+
+use crate::{cmd, Result};
+
+#[derive(Args)]
+pub struct DocTask {
+    /// Open the browser when the docs are built.
+    #[clap(long)]
+    pub open: bool,
+
+    /// Fail on warnings.
+    #[clap(long)]
+    pub deny_warnings: bool,
+}
+
+impl DocTask {
+    pub(crate) fn run(self) -> Result<()> {
+        let mut rustdocflags = "--enable-index-page -Zunstable-options --cfg docsrs".to_owned();
+        if self.deny_warnings {
+            rustdocflags += " -Dwarnings";
+        }
+
+        // Keep in sync with .github/workflows/docs.yml
+        let mut cmd = cmd!(
+            "
+            rustup run nightly cargo doc --no-deps --workspace
+            --exclude ruma-macros --exclude ruma-identifiers-validation --exclude xtask
+            --all-features -Zrustdoc-map
+            "
+        )
+        .env("RUSTDOCFLAGS", rustdocflags);
+
+        if self.open {
+            cmd = cmd.arg("--open");
+        }
+
+        cmd.run()?;
+
+        Ok(())
+    }
+}
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index f30892d2..719d1dfc 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -14,12 +14,14 @@ use serde_json::from_str as from_json_str;
 #[cfg(feature = "default")]
 mod cargo;
 mod ci;
+mod doc;
 #[cfg(feature = "default")]
 mod release;
 #[cfg(feature = "default")]
 mod util;
 
 use ci::{CiArgs, CiTask};
+use doc::DocTask;
 #[cfg(feature = "default")]
 use release::{ReleaseArgs, ReleaseTask};
 
@@ -35,6 +37,8 @@ struct Xtask {
 enum Command {
     /// Run continuous integration checks
     Ci(CiArgs),
+    /// Build the docs
+    Doc(DocTask),
     /// Publish a new version of a crate on crates.io, `publish` can be used as an alias
     #[cfg(feature = "default")]
     #[clap(alias = "publish")]
@@ -47,6 +51,7 @@ fn main() -> Result<()> {
             let ci = CiTask::new(args.cmd)?;
             ci.run()
         }
+        Command::Doc(doc) => doc.run(),
         #[cfg(feature = "default")]
         Command::Release(args) => {
             let mut task = ReleaseTask::new(args.package, args.version)?;