diff --git a/src/main.rs b/src/main.rs
index b78235e..7b561a4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,15 +1,14 @@
+use anyhow::Context as _;
 use cargo::core::dependency::DepKind;
 use cargo::core::resolver::Resolve;
-use cargo::core::{Package, SourceId, Workspace};
+use cargo::core::{FeatureValue, Package, SourceId, Workspace};
 use cargo::sources::PathSource;
 use cargo::util::errors::*;
-use anyhow::{Context as _};
 use cargo::util::Config;
 use cargo_platform::Platform;
 use docopt::Docopt;
 use flate2::write::GzEncoder;
 use serde::{Deserialize, Serialize};
-use url::Url;
 use std::collections::{BTreeMap, HashSet};
 use std::env;
 use std::fs::{self, File};
@@ -17,6 +16,7 @@ use std::io;
 use std::io::prelude::*;
 use std::path::{self, Path, PathBuf};
 use tar::{Builder, Header};
+use url::Url;
 
 #[derive(Deserialize)]
 struct Options {
@@ -49,7 +49,7 @@ struct RegistryDependency {
     default_features: bool,
     target: Option<String>,
     kind: Option<String>,
-    package: Option<String>
+    package: Option<String>,
 }
 
 fn main() {
@@ -104,7 +104,7 @@ fn real_main(options: Options, config: &mut Config) -> CargoResult<()> {
         /* offline = */ false,
         /* target dir = */ &None,
         /* unstable flags = */ &[],
-        /* cli_config = */ &[]
+        /* cli_config = */ &[],
     )?;
 
     let path = Path::new(&options.arg_path);
@@ -203,7 +203,7 @@ fn sync(
             _ => index_dir.join(&name[..2]).join(&name[2..4]).join(name),
         };
         fs::create_dir_all(&dst.parent().unwrap())?;
-        let line = serde_json::to_string(&registry_pkg(&pkg, &resolve)).unwrap();
+        let line = serde_json::to_string(&registry_pkg(&pkg, &resolve, &config)).unwrap();
 
         let prev = if no_delete || added_index.contains(&dst) {
             read(&dst).unwrap_or(String::new())
@@ -297,7 +297,7 @@ fn build_ar(ar: &mut Builder<GzEncoder<File>>, pkg: &Package, config: &Config) {
     }
 }
 
-fn registry_pkg(pkg: &Package, resolve: &Resolve) -> RegistryPackage {
+fn registry_pkg(pkg: &Package, resolve: &Resolve, config: &Config) -> RegistryPackage {
     let id = pkg.package_id();
     let mut deps = pkg
         .dependencies()
@@ -329,17 +329,38 @@ fn registry_pkg(pkg: &Package, resolve: &Resolve) -> RegistryPackage {
         .collect::<Vec<_>>();
     deps.sort();
 
+    let allow_namespaced_features =
+        config.nightly_features_allowed && config.cli_unstable().namespaced_features;
     let features = pkg
         .summary()
         .features()
         .into_iter()
-        .map(|(k, v)| {
+        .filter_map(|(k, v)| {
+            if !allow_namespaced_features
+                && !v.is_empty()
+                && v.iter().all(|fv| {
+                    if let FeatureValue::Dep { .. } = fv {
+                        true
+                    } else {
+                        false
+                    }
+                })
+            {
+                return None;
+            }
             let mut v = v
                 .iter()
-                .map(|x| x.to_string())
+                .filter_map(|fv| {
+                    if !allow_namespaced_features {
+                        if let FeatureValue::Dep { .. } = fv {
+                            return None;
+                        }
+                    }
+                    Some(fv.to_string())
+                })
                 .collect::<Vec<_>>();
             v.sort();
-            (k.to_string(), v)
+            Some((k.to_string(), v))
         })
         .collect();
 
diff --git a/tests/all.rs b/tests/all.rs
index 625bb63..414df8b 100644
--- a/tests/all.rs
+++ b/tests/all.rs
@@ -317,7 +317,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
     File::open(registry.join("index/in/fl/inflector")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"Inflector","vers":"0.11.3","deps":[{"name":"lazy_static","req":"^1.0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"regex","req":"^1.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"4467f98bb61f615f8273359bf1c989453dfc1ea4a45ae9298f1dcd0672febe5d","features":{"default":["heavyweight"],"heavyweight":["lazy_static","regex"],"lazy_static":["dep:lazy_static"],"regex":["dep:regex"],"unstable":[]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"Inflector","vers":"0.11.3","deps":[{"name":"lazy_static","req":"^1.0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"regex","req":"^1.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"4467f98bb61f615f8273359bf1c989453dfc1ea4a45ae9298f1dcd0672febe5d","features":{"default":["heavyweight"],"heavyweight":["lazy_static","regex"],"unstable":[]},"yanked":false}"#);
 }
 
 #[test]
@@ -359,7 +359,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
     File::open(registry.join("index/ru/st/rustc-demangle")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"rustc-demangle","vers":"0.1.14","deps":[{"name":"compiler_builtins","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"core","req":"^1.0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":"rustc-std-workspace-core"}],"cksum":"ccc78bfd5acd7bf3e89cffcf899e5cb1a52d6fafa8dec2739ad70c9577a57288","features":{"compiler_builtins":["dep:compiler_builtins"],"core":["dep:core"],"rustc-dep-of-std":["compiler_builtins","core"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"rustc-demangle","vers":"0.1.14","deps":[{"name":"compiler_builtins","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"core","req":"^1.0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":"rustc-std-workspace-core"}],"cksum":"ccc78bfd5acd7bf3e89cffcf899e5cb1a52d6fafa8dec2739ad70c9577a57288","features":{"rustc-dep-of-std":["compiler_builtins","core"]},"yanked":false}"#);
 }
 
 #[test]
@@ -410,12 +410,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
     let mut contents = String::new();
     File::open(registry.join("index/la/zy/lazy_static")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"lazy_static","vers":"0.2.11","deps":[{"name":"compiletest_rs","req":"^0.3","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"spin","req":"^0.4.6","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"76f033c7ad61445c5b347c7382dd1237847eb1bce590fe50365dcb33d546be73","features":{"compiletest":["compiletest_rs"],"compiletest_rs":["dep:compiletest_rs"],"nightly":[],"spin":["dep:spin"],"spin_no_std":["nightly","spin"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"lazy_static","vers":"0.2.11","deps":[{"name":"compiletest_rs","req":"^0.3","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"spin","req":"^0.4.6","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"76f033c7ad61445c5b347c7382dd1237847eb1bce590fe50365dcb33d546be73","features":{"compiletest":["compiletest_rs"],"nightly":[],"spin_no_std":["nightly","spin"]},"yanked":false}"#);
 
     contents.clear();
     File::open(registry.join("index/la/ng/language-tags")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"language-tags","vers":"0.2.2","deps":[{"name":"heapsize","req":">=0.2.2, <0.4","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"heapsize_plugin","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"a91d884b6667cd606bb5a69aa0c99ba811a115fc68915e7056ec08a46e93199a","features":{"heap_size":["heapsize","heapsize_plugin"],"heapsize":["dep:heapsize"],"heapsize_plugin":["dep:heapsize_plugin"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"language-tags","vers":"0.2.2","deps":[{"name":"heapsize","req":">=0.2.2, <0.4","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"heapsize_plugin","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"a91d884b6667cd606bb5a69aa0c99ba811a115fc68915e7056ec08a46e93199a","features":{"heap_size":["heapsize","heapsize_plugin"]},"yanked":false}"#);
 
     // Modify the Cargo.toml to swap an existing library, add a new one and delete another
     File::create(&td.path().join("Cargo.toml")).unwrap().write_all(br#"
@@ -464,18 +464,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
     contents.clear();
     File::open(registry.join("index/la/zy/lazy_static")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"lazy_static","vers":"0.2.11","deps":[{"name":"compiletest_rs","req":"^0.3","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"spin","req":"^0.4.6","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"76f033c7ad61445c5b347c7382dd1237847eb1bce590fe50365dcb33d546be73","features":{"compiletest":["compiletest_rs"],"compiletest_rs":["dep:compiletest_rs"],"nightly":[],"spin":["dep:spin"],"spin_no_std":["nightly","spin"]},"yanked":false}
-{"name":"lazy_static","vers":"1.2.0","deps":[{"name":"spin","req":"^0.4.10","features":["once"],"optional":true,"default_features":false,"target":null,"kind":null,"package":null}],"cksum":"a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1","features":{"nightly":[],"spin":["dep:spin"],"spin_no_std":["spin"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"lazy_static","vers":"0.2.11","deps":[{"name":"compiletest_rs","req":"^0.3","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"spin","req":"^0.4.6","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"76f033c7ad61445c5b347c7382dd1237847eb1bce590fe50365dcb33d546be73","features":{"compiletest":["compiletest_rs"],"nightly":[],"spin_no_std":["nightly","spin"]},"yanked":false}
+{"name":"lazy_static","vers":"1.2.0","deps":[{"name":"spin","req":"^0.4.10","features":["once"],"optional":true,"default_features":false,"target":null,"kind":null,"package":null}],"cksum":"a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1","features":{"nightly":[],"spin_no_std":["spin"]},"yanked":false}"#);
 
     contents.clear();
     File::open(registry.join("index/la/zy/lazycell")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"lazycell","vers":"1.2.1","deps":[{"name":"clippy","req":"^0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f","features":{"clippy":["dep:clippy"],"nightly":[],"nightly-testing":["clippy","nightly"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"lazycell","vers":"1.2.1","deps":[{"name":"clippy","req":"^0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f","features":{"nightly":[],"nightly-testing":["clippy","nightly"]},"yanked":false}"#);
 
     contents.clear();
     File::open(registry.join("index/la/ng/language-tags")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"language-tags","vers":"0.2.2","deps":[{"name":"heapsize","req":">=0.2.2, <0.4","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"heapsize_plugin","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"a91d884b6667cd606bb5a69aa0c99ba811a115fc68915e7056ec08a46e93199a","features":{"heap_size":["heapsize","heapsize_plugin"],"heapsize":["dep:heapsize"],"heapsize_plugin":["dep:heapsize_plugin"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"language-tags","vers":"0.2.2","deps":[{"name":"heapsize","req":">=0.2.2, <0.4","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null},{"name":"heapsize_plugin","req":"^0.1.2","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"a91d884b6667cd606bb5a69aa0c99ba811a115fc68915e7056ec08a46e93199a","features":{"heap_size":["heapsize","heapsize_plugin"]},"yanked":false}"#);
 
     // Run for the third time -- delete unused (default)
     run(cmd().arg(&registry).arg("--sync").arg(&lock));
@@ -493,12 +493,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
     contents.clear();
     File::open(registry.join("index/la/zy/lazy_static")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"lazy_static","vers":"1.2.0","deps":[{"name":"spin","req":"^0.4.10","features":["once"],"optional":true,"default_features":false,"target":null,"kind":null,"package":null}],"cksum":"a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1","features":{"nightly":[],"spin":["dep:spin"],"spin_no_std":["spin"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"lazy_static","vers":"1.2.0","deps":[{"name":"spin","req":"^0.4.10","features":["once"],"optional":true,"default_features":false,"target":null,"kind":null,"package":null}],"cksum":"a374c89b9db55895453a74c1e38861d9deec0b01b405a82516e9d5de4820dea1","features":{"nightly":[],"spin_no_std":["spin"]},"yanked":false}"#);
 
     contents.clear();
     File::open(registry.join("index/la/zy/lazycell")).unwrap()
         .read_to_string(&mut contents).unwrap();
-    assert_eq!(contents, r#"{"name":"lazycell","vers":"1.2.1","deps":[{"name":"clippy","req":"^0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f","features":{"clippy":["dep:clippy"],"nightly":[],"nightly-testing":["clippy","nightly"]},"yanked":false}"#);
+    assert_eq!(contents, r#"{"name":"lazycell","vers":"1.2.1","deps":[{"name":"clippy","req":"^0.0","features":[],"optional":true,"default_features":true,"target":null,"kind":null,"package":null}],"cksum":"b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f","features":{"nightly":[],"nightly-testing":["clippy","nightly"]},"yanked":false}"#);
 }
 
 fn run(cmd: &mut Command) -> String {