diff --git a/Cargo.lock b/Cargo.lock
index 9e134aa95..c54cc2e97 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1772,9 +1772,9 @@ dependencies = [
 
 [[package]]
 name = "wit-parser"
-version = "0.6.0"
+version = "0.6.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e0fe225a32528b42a7037add1b5ed1dff83288f21a067007b34565ce87fc2c7"
+checksum = "a84965789410bf21087f5a352703142f77b9b4d1478764c3f33a1ea8c7101f40"
 dependencies = [
  "anyhow",
  "id-arena",
diff --git a/Cargo.toml b/Cargo.toml
index e04b5b59b..b4d5a91a3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,7 +32,7 @@ indexmap = "1.9.1"
 wasm-encoder = "0.24.0"
 wasm-metadata = "0.2.0"
 wat = "1.0.59"
-wit-parser = "0.6.0"
+wit-parser = "0.6.1"
 wit-component = "0.7.0"
 
 wit-bindgen-core = { path = 'crates/bindgen-core', version = '0.3.0' }
diff --git a/crates/guest-rust-macro/src/lib.rs b/crates/guest-rust-macro/src/lib.rs
index cb60a761f..619ead9b0 100644
--- a/crates/guest-rust-macro/src/lib.rs
+++ b/crates/guest-rust-macro/src/lib.rs
@@ -33,11 +33,10 @@ impl Parse for Config {
         let mut world = None;
         let mut source = None;
 
-        let document = if input.peek(token::Brace) {
+        if input.peek(token::Brace) {
             let content;
             syn::braced!(content in input);
             let fields = Punctuated::<Opt, Token![,]>::parse_terminated(&content)?;
-            let mut document = None;
             for field in fields.into_pairs() {
                 match field.into_value() {
                     Opt::Path(s) => {
@@ -47,10 +46,10 @@ impl Parse for Config {
                         source = Some(Source::Path(s.value()));
                     }
                     Opt::World(s) => {
-                        if document.is_some() {
-                            return Err(Error::new(s.span(), "cannot specify second document"));
+                        if world.is_some() {
+                            return Err(Error::new(s.span(), "cannot specify second world"));
                         }
-                        document = Some(parse_doc(&s.value(), &mut world));
+                        world = Some(s.value());
                     }
                     Opt::Inline(s) => {
                         if source.is_some() {
@@ -67,43 +66,17 @@ impl Parse for Config {
                     Opt::Skip(list) => opts.skip.extend(list.iter().map(|i| i.value())),
                 }
             }
-            match (document, &source) {
-                (Some(doc), _) => doc,
-                (None, Some(Source::Inline(_))) => "macro-input".to_string(),
-                _ => {
-                    return Err(Error::new(
-                        call_site,
-                        "must specify a `world` to generate bindings for",
-                    ))
-                }
-            }
         } else {
-            let document = input.parse::<syn::LitStr>()?;
+            world = input.parse::<Option<syn::LitStr>>()?.map(|s| s.value());
             if input.parse::<Option<syn::token::In>>()?.is_some() {
                 source = Some(Source::Path(input.parse::<syn::LitStr>()?.value()));
             }
-            parse_doc(&document.value(), &mut world)
-        };
+        }
         let (resolve, pkg, files) =
             parse_source(&source).map_err(|err| Error::new(call_site, format!("{err:?}")))?;
-        let doc = resolve.packages[pkg]
-            .documents
-            .get(&document)
-            .copied()
-            .ok_or_else(|| {
-                Error::new(call_site, format!("no document named `{document}` found"))
-            })?;
-
-        let world = match &world {
-            Some(name) => resolve.documents[doc]
-                .worlds
-                .get(name)
-                .copied()
-                .ok_or_else(|| Error::new(call_site, format!("no world named `{name}` found")))?,
-            None => resolve.documents[doc].default_world.ok_or_else(|| {
-                Error::new(call_site, format!("no default world found in `{document}`"))
-            })?,
-        };
+        let world = resolve
+            .select_world(pkg, world.as_deref())
+            .map_err(|e| Error::new(call_site, format!("{e:?}")))?;
         Ok(Config {
             opts,
             resolve,
@@ -140,16 +113,6 @@ fn parse_source(source: &Option<Source>) -> anyhow::Result<(Resolve, PackageId,
     Ok((resolve, pkg, files))
 }
 
-fn parse_doc(s: &str, world: &mut Option<String>) -> String {
-    match s.find('.') {
-        Some(pos) => {
-            *world = Some(s[pos + 1..].to_string());
-            s[..pos].to_string()
-        }
-        None => s.to_string(),
-    }
-}
-
 impl Config {
     fn expand(self) -> Result<TokenStream> {
         let mut files = Default::default();
diff --git a/crates/test-helpers/src/lib.rs b/crates/test-helpers/src/lib.rs
index 1ec03ec97..361bd7432 100644
--- a/crates/test-helpers/src/lib.rs
+++ b/crates/test-helpers/src/lib.rs
@@ -135,11 +135,6 @@ fn parse_wit(path: &Path) -> (Resolve, WorldId) {
             )
             .unwrap()
     };
-    let world = resolve.packages[pkg]
-        .documents
-        .iter()
-        .filter_map(|(_, doc)| resolve.documents[*doc].default_world)
-        .next()
-        .expect("no `default world` found");
+    let world = resolve.select_world(pkg, None).unwrap();
     (resolve, world)
 }
diff --git a/src/bin/wit-bindgen.rs b/src/bin/wit-bindgen.rs
index fec775d95..080eff496 100644
--- a/src/bin/wit-bindgen.rs
+++ b/src/bin/wit-bindgen.rs
@@ -1,4 +1,4 @@
-use anyhow::{anyhow, bail, Context, Result};
+use anyhow::{bail, Context, Result};
 use clap::Parser;
 use std::path::PathBuf;
 use std::str;
@@ -142,44 +142,7 @@ fn gen_world(
             &Default::default(),
         )?
     };
-    let world = match &opts.world {
-        Some(world) => {
-            let mut parts = world.splitn(2, '.');
-            let doc = parts.next().unwrap();
-            let world = parts.next();
-            let doc = *resolve.packages[pkg]
-                .documents
-                .get(doc)
-                .ok_or_else(|| anyhow!("no document named `{doc}` in package"))?;
-            match world {
-                Some(name) => *resolve.documents[doc]
-                    .worlds
-                    .get(name)
-                    .ok_or_else(|| anyhow!("no world named `{name}` in document"))?,
-                None => resolve.documents[doc]
-                    .default_world
-                    .ok_or_else(|| anyhow!("no default world in document"))?,
-            }
-        }
-        None => {
-            if resolve.packages[pkg].documents.is_empty() {
-                bail!("no documents found in package")
-            }
-
-            let mut unique_default_world = None;
-            for (_name, doc) in &resolve.documents {
-                if let Some(default_world) = doc.default_world {
-                    if unique_default_world.is_some() {
-                        bail!("multiple default worlds found in package, specify which to bind with `--world` argument")
-                    } else {
-                        unique_default_world = Some(default_world);
-                    }
-                }
-            }
-
-            unique_default_world.ok_or_else(|| anyhow!("no default world in package"))?
-        }
-    };
+    let world = resolve.select_world(pkg, opts.world.as_deref())?;
     generator.generate(&resolve, world, files);
     Ok(())
 }
diff --git a/tests/runtime/main.rs b/tests/runtime/main.rs
index 6f1f94494..4de7745a9 100644
--- a/tests/runtime/main.rs
+++ b/tests/runtime/main.rs
@@ -76,12 +76,7 @@ fn tests(name: &str) -> Result<Vec<PathBuf>> {
 
     let mut resolve = Resolve::new();
     let (pkg, _files) = resolve.push_dir(&dir).unwrap();
-    let world = resolve.packages[pkg]
-        .documents
-        .iter()
-        .filter_map(|(_, doc)| resolve.documents[*doc].default_world)
-        .next()
-        .expect("no default world found");
+    let world = resolve.select_world(pkg, None).unwrap();
 
     let mut rust = Vec::new();
     let mut c = Vec::new();