diff --git a/Cargo.lock b/Cargo.lock
index 55a3ecc0d5..bb1b924183 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -126,6 +126,7 @@ dependencies = [
  "assert_cli",
  "atty",
  "cargo_metadata",
+ "crates-index",
  "dirs-next",
  "env_proxy",
  "error-chain",
@@ -244,6 +245,24 @@ dependencies = [
  "unreachable",
 ]
 
+[[package]]
+name = "crates-index"
+version = "0.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ad4af5c8dd9940a497ef4473e6e558b660a4a1b6e5ce2cb9d85454e2aaaf947"
+dependencies = [
+ "git2",
+ "glob",
+ "hex",
+ "home",
+ "memchr",
+ "semver",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "smartstring",
+]
+
 [[package]]
 name = "ctor"
 version = "0.1.18"
@@ -364,9 +383,9 @@ checksum = "f6503fe142514ca4799d4c26297c4248239fe8838d827db6bd6065c6ed29a6ce"
 
 [[package]]
 name = "git2"
-version = "0.13.17"
+version = "0.13.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d250f5f82326884bd39c2853577e70a121775db76818ffa452ed1e80de12986"
+checksum = "659cd14835e75b64d9dba5b660463506763cf0aa6cb640aeeb0e98d841093490"
 dependencies = [
  "bitflags",
  "libc",
@@ -377,6 +396,12 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "heck"
 version = "0.3.2"
@@ -397,9 +422,21 @@ dependencies = [
 
 [[package]]
 name = "hex"
-version = "0.4.2"
+version = "0.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "644f9158b2f133fd50f5fb3242878846d9eb792e445c893805ff0e3824006e35"
+checksum = "7f24254aa9a54b5c858eaee2f5bccdb46aaf0e486a595ed5fd8f86ba55232a70"
+dependencies = [
+ "serde",
+]
+
+[[package]]
+name = "home"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2456aef2e6b6a9784192ae780c0f15bc57df0e918585282325e8c8ac27737654"
+dependencies = [
+ "winapi 0.3.9",
+]
 
 [[package]]
 name = "idna"
@@ -450,9 +487,9 @@ checksum = "1cca32fa0182e8c0989459524dc356b8f2b5c10f1b9eb521b7d182c03cf8c5ff"
 
 [[package]]
 name = "libgit2-sys"
-version = "0.12.18+1.1.0"
+version = "0.12.22+1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3da6a42da88fc37ee1ecda212ffa254c25713532980005d5f7c0b0fbe7e6e885"
+checksum = "89c53ac117c44f7042ad8d8f5681378dfbc6010e49ec2c0d1f11dfedc7a4a1c3"
 dependencies = [
  "cc",
  "libc",
@@ -511,9 +548,9 @@ checksum = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
 
 [[package]]
 name = "memchr"
-version = "2.3.4"
+version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 
 [[package]]
 name = "miniz_oxide"
@@ -822,18 +859,18 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.123"
+version = "1.0.129"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92d5161132722baa40d802cc70b15262b98258453e85e5d1d365c757c73869ae"
+checksum = "d1f72836d2aa753853178eda473a3b9d8e4eefdaf20523b919677e6de489f8f1"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.123"
+version = "1.0.129"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9391c295d64fc0abb2c556bad848f33cb8296276b1ad2677d1ae1ace4f258f31"
+checksum = "e57ae87ad533d9a56427558b516d0adac283614e347abf85b0dc0cbbf0a249f3"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -842,15 +879,25 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.61"
+version = "1.0.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4fceb2595057b6891a4ee808f70054bd2d12f0e97f1cbb78689b59f676df325a"
+checksum = "336b10da19a12ad094b59d870ebde26a45402e5b470add4b5fd03c5048a32127"
 dependencies = [
  "itoa",
  "ryu",
  "serde",
 ]
 
+[[package]]
+name = "smartstring"
+version = "0.2.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "31aa6a31c0c2b21327ce875f7e8952322acfcfd0c27569a6e18a647281352c9b"
+dependencies = [
+ "serde",
+ "static_assertions",
+]
+
 [[package]]
 name = "socks"
 version = "0.3.3"
@@ -869,6 +916,12 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
+[[package]]
+name = "static_assertions"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
+
 [[package]]
 name = "strsim"
 version = "0.8.0"
diff --git a/Cargo.toml b/Cargo.toml
index 4fb854c000..844e3ca74d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -46,6 +46,7 @@ required-features = ["upgrade"]
 [dependencies]
 atty = { version = "0.2.14", optional = true }
 cargo_metadata = "0.14.0"
+crates-index = "0.17.0"
 dirs-next = "2.0.0"
 env_proxy = "0.4.1"
 error-chain = "0.12.4"
diff --git a/src/errors.rs b/src/errors.rs
index 6d30599413..91bdf0cb1f 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -5,6 +5,8 @@ error_chain! {
         Io(::std::io::Error) #[doc = "An error from the std::io module"];
         Git(::git2::Error)#[doc = "An error from the git2 crate"];
         CargoMetadata(::failure::Compat<::cargo_metadata::Error>)#[doc = "An error from the cargo_metadata crate"];
+        Semver(::semver::Error)#[doc = "An error from the semver crate"];
+        CratesIndex(::crates_index::Error)#[doc = "An error from the crates-index crate"];
     }
 
     errors {
diff --git a/src/fetch.rs b/src/fetch.rs
index 7dde3b88fa..6bfee89da5 100644
--- a/src/fetch.rs
+++ b/src/fetch.rs
@@ -1,19 +1,18 @@
 use crate::errors::*;
-use crate::registry::{registry_path, registry_path_from_url};
+use crate::registry::registry_url;
 use crate::VersionExt;
 use crate::{Dependency, Manifest};
 use regex::Regex;
 use std::env;
 use std::io::Write;
-use std::path::{Path, PathBuf};
+use std::path::Path;
 use std::time::Duration;
 use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 use url::Url;
 
-#[derive(Deserialize)]
+#[derive(Debug)]
 struct CrateVersion {
     name: String,
-    #[serde(rename = "vers")]
     version: semver::Version,
     yanked: bool,
 }
@@ -54,12 +53,12 @@ pub fn get_latest_dependency(
         return Err(ErrorKind::EmptyCrateName.into());
     }
 
-    let registry_path = match registry {
-        Some(url) => registry_path_from_url(url)?,
-        None => registry_path(manifest_path, None)?,
+    let registry = match registry {
+        Some(url) => url.clone(),
+        None => registry_url(manifest_path, None)?,
     };
 
-    let crate_versions = fuzzy_query_registry_index(crate_name, &registry_path)?;
+    let crate_versions = fuzzy_query_registry_index(crate_name, &registry)?;
 
     let dep = read_latest_version(&crate_versions, flag_allow_prerelease)?;
 
@@ -94,8 +93,6 @@ fn read_latest_version(
 
 /// update registry index for given project
 pub fn update_registry_index(registry: &Url, quiet: bool) -> Result<()> {
-    let registry_path = registry_path_from_url(registry)?;
-
     let colorchoice = if atty::is(atty::Stream::Stdout) {
         ColorChoice::Auto
     } else {
@@ -103,19 +100,8 @@ pub fn update_registry_index(registry: &Url, quiet: bool) -> Result<()> {
     };
     let mut output = StandardStream::stdout(colorchoice);
 
-    if !registry_path.as_path().exists() {
-        output.set_color(ColorSpec::new().set_fg(Some(Color::Green)).set_bold(true))?;
-        write!(output, "{:>12}", "Initializing")?;
-        output.reset()?;
-        writeln!(output, " '{}' index", registry)?;
-
-        let mut opts = git2::RepositoryInitOptions::new();
-        opts.bare(true);
-        git2::Repository::init_opts(&registry_path, &opts)?;
-        return Ok(());
-    }
-
-    let repo = git2::Repository::open(&registry_path)?;
+    let index = crates_index::BareIndex::from_url(registry.as_str())?;
+    let mut index = index.open_or_clone()?;
     if !quiet {
         output.set_color(ColorSpec::new().set_fg(Some(Color::Green)).set_bold(true))?;
         write!(output, "{:>12}", "Updating")?;
@@ -123,62 +109,55 @@ pub fn update_registry_index(registry: &Url, quiet: bool) -> Result<()> {
         writeln!(output, " '{}' index", registry)?;
     }
 
-    let refspec = format!(
-        "refs/heads/{0}:refs/remotes/origin/{0}",
-        get_checkout_name(registry_path)?
-    );
-    fetch_with_cli(&repo, registry.as_str(), &refspec)?;
+    while let Err(err) = index.retrieve() {
+        if need_retry(err)? {
+            registry_blocked_message(&mut output)?;
+            std::thread::sleep(REGISTRY_BACKOFF);
+        } else {
+            break;
+        }
+    }
 
     Ok(())
 }
 
-// https://github.com/rust-lang/cargo/blob/57986eac7157261c33f0123bade7ccd20f15200f/src/cargo/sources/git/utils.rs#L758
-fn fetch_with_cli(repo: &git2::Repository, url: &str, refspec: &str) -> Result<()> {
-    let cmd = subprocess::Exec::shell("git")
-        .arg("fetch")
-        .arg("--tags") // fetch all tags
-        .arg("--force") // handle force pushes
-        .arg("--update-head-ok") // see discussion in rust-lang/cargo#2078
-        .arg(url)
-        .arg(refspec)
-        // If cargo is run by git (for example, the `exec` command in `git
-        // rebase`), the GIT_DIR is set by git and will point to the wrong
-        // location (this takes precedence over the cwd). Make sure this is
-        // unset so git will look at cwd for the repo.
-        .env_remove("GIT_DIR")
-        // The reset of these may not be necessary, but I'm including them
-        // just to be extra paranoid and avoid any issues.
-        .env_remove("GIT_WORK_TREE")
-        .env_remove("GIT_INDEX_FILE")
-        .env_remove("GIT_OBJECT_DIRECTORY")
-        .env_remove("GIT_ALTERNATE_OBJECT_DIRECTORIES")
-        .cwd(repo.path());
-
-    let _ = cmd.capture().map_err(|e| match e {
-        subprocess::PopenError::IoError(io) => ErrorKind::Io(io),
-        _ => unreachable!("expected only io error"),
-    })?;
+const REGISTRY_BACKOFF: Duration = Duration::from_secs(1);
+
+fn need_retry(err: crates_index::Error) -> Result<bool> {
+    match err {
+        crates_index::Error::Git(err) => {
+            if err.class() == git2::ErrorClass::Index && err.code() == git2::ErrorCode::Locked {
+                Ok(true)
+            } else {
+                Err(crates_index::Error::Git(err).into())
+            }
+        }
+        err => Err(err.into()),
+    }
+}
+
+fn registry_blocked_message(output: &mut StandardStream) -> Result<()> {
+    output.set_color(ColorSpec::new().set_fg(Some(Color::Green)).set_bold(true))?;
+    write!(output, "{:>12}", "Blocking")?;
+    output.reset()?;
+    writeln!(output, " waiting for lock on registry index")?;
     Ok(())
 }
 
 #[test]
-fn get_latest_stable_version_from_json() {
-    let versions: Vec<CrateVersion> = serde_json::from_str(
-        r#"[
-        {
-          "name": "foo",
-          "vers": "0.6.0-alpha",
-          "yanked": false
+fn get_latest_stable_version() {
+    let versions = vec![
+        CrateVersion {
+            name: "foo".into(),
+            version: "0.6.0-alpha".parse().unwrap(),
+            yanked: false,
         },
-        {
-          "name": "foo",
-          "vers": "0.5.0",
-          "yanked": false
-        }
-      ]"#,
-    )
-    .expect("crate version is correctly parsed");
-
+        CrateVersion {
+            name: "foo".into(),
+            version: "0.5.0".parse().unwrap(),
+            yanked: false,
+        },
+    ];
     assert_eq!(
         read_latest_version(&versions, false)
             .unwrap()
@@ -189,23 +168,19 @@ fn get_latest_stable_version_from_json() {
 }
 
 #[test]
-fn get_latest_unstable_or_stable_version_from_json() {
-    let versions: Vec<CrateVersion> = serde_json::from_str(
-        r#"[
-        {
-          "name": "foo",
-          "vers": "0.6.0-alpha",
-          "yanked": false
+fn get_latest_unstable_or_stable_version() {
+    let versions = vec![
+        CrateVersion {
+            name: "foo".into(),
+            version: "0.6.0-alpha".parse().unwrap(),
+            yanked: false,
         },
-        {
-          "name": "foo",
-          "vers": "0.5.0",
-          "yanked": false
-        }
-      ]"#,
-    )
-    .expect("crate version is correctly parsed");
-
+        CrateVersion {
+            name: "foo".into(),
+            version: "0.5.0".parse().unwrap(),
+            yanked: false,
+        },
+    ];
     assert_eq!(
         read_latest_version(&versions, true)
             .unwrap()
@@ -216,23 +191,19 @@ fn get_latest_unstable_or_stable_version_from_json() {
 }
 
 #[test]
-fn get_latest_version_from_json_test() {
-    let versions: Vec<CrateVersion> = serde_json::from_str(
-        r#"[
-        {
-          "name": "treexml",
-          "vers": "0.3.1",
-          "yanked": true
+fn get_latest_version_with_yanked() {
+    let versions = vec![
+        CrateVersion {
+            name: "treexml".into(),
+            version: "0.3.1".parse().unwrap(),
+            yanked: true,
         },
-        {
-          "name": "treexml",
-          "vers": "0.3.0",
-          "yanked": false
-        }
-      ]"#,
-    )
-    .expect("crate version is correctly parsed");
-
+        CrateVersion {
+            name: "true".into(),
+            version: "0.3.0".parse().unwrap(),
+            yanked: false,
+        },
+    ];
     assert_eq!(
         read_latest_version(&versions, false)
             .unwrap()
@@ -244,61 +215,30 @@ fn get_latest_version_from_json_test() {
 
 #[test]
 fn get_no_latest_version_from_json_when_all_are_yanked() {
-    let versions: Vec<CrateVersion> = serde_json::from_str(
-        r#"[
-        {
-          "name": "treexml",
-          "vers": "0.3.1",
-          "yanked": true
+    let versions = vec![
+        CrateVersion {
+            name: "treexml".into(),
+            version: "0.3.1".parse().unwrap(),
+            yanked: true,
         },
-        {
-          "name": "treexml",
-          "vers": "0.3.0",
-          "yanked": true
-        }
-      ]"#,
-    )
-    .expect("crate version is correctly parsed");
-
+        CrateVersion {
+            name: "true".into(),
+            version: "0.3.0".parse().unwrap(),
+            yanked: true,
+        },
+    ];
     assert!(read_latest_version(&versions, false).is_err());
 }
 
-/// Gets the checkedout branch name of .cargo/registry/index/github.com-*/.git/refs or
-/// .cargo/registry/index/github.com-*/refs for bare git repository
-fn get_checkout_name(registry_path: impl AsRef<Path>) -> Result<String> {
-    let checkout_dir = registry_path
-        .as_ref()
-        .join(".git")
-        .join("refs/remotes/origin/");
-    let bare_checkout_dir = registry_path.as_ref().join("refs/remotes/origin/");
-
-    Ok(checkout_dir
-        .read_dir() // .git repo
-        .or_else(|_| bare_checkout_dir.read_dir())? // there's no .git, it's bare one
-        .next() //Is there always only one branch? (expecting either master og HEAD)
-        .ok_or(ErrorKind::MissingRegistraryCheckout(checkout_dir))??
-        .file_name()
-        .into_string()
-        .map_err(|_| ErrorKind::NonUnicodeGitPath)?)
-}
-
 /// Fuzzy query crate from registry index
 fn fuzzy_query_registry_index(
     crate_name: impl Into<String>,
-    registry_path: impl AsRef<Path>,
+    registry: &Url,
 ) -> Result<Vec<CrateVersion>> {
-    let crate_name = crate_name.into();
-    let remotes = PathBuf::from("refs/remotes/origin/");
-    let repo = git2::Repository::open(&registry_path)?;
-    let tree = repo
-        .find_reference(
-            remotes
-                .join(get_checkout_name(&registry_path)?)
-                .to_str()
-                .ok_or(ErrorKind::NonUnicodeGitPath)?,
-        )?
-        .peel_to_tree()?;
+    let index = crates_index::BareIndex::from_url(registry.as_str())?;
+    let index = index.open_or_clone()?;
 
+    let crate_name = crate_name.into();
     let mut names = gen_fuzzy_crate_names(crate_name.clone())?;
     if let Some(index) = names.iter().position(|x| *x == crate_name) {
         // ref: https://github.com/killercup/cargo-edit/pull/317#discussion_r307365704
@@ -306,20 +246,21 @@ fn fuzzy_query_registry_index(
     }
 
     for the_name in names {
-        let file = match tree.get_path(&PathBuf::from(summary_raw_path(&the_name))) {
-            Ok(x) => x.to_object(&repo)?.peel_to_blob()?,
-            Err(_) => continue,
+        let crate_ = match index.crate_(&the_name) {
+            Some(crate_) => crate_,
+            None => continue,
         };
-        let content = String::from_utf8(file.content().to_vec())
-            .map_err(|_| ErrorKind::InvalidSummaryJson)?;
-
-        return content
-            .lines()
-            .map(|line: &str| {
-                serde_json::from_str::<CrateVersion>(line)
-                    .map_err(|_| ErrorKind::InvalidSummaryJson.into())
+        return crate_
+            .versions()
+            .iter()
+            .map(|v| {
+                Ok(CrateVersion {
+                    name: v.name().to_owned(),
+                    version: v.version().parse()?,
+                    yanked: v.is_yanked(),
+                })
             })
-            .collect::<Result<Vec<CrateVersion>>>();
+            .collect();
     }
     Err(ErrorKind::NoCrate(crate_name).into())
 }
@@ -490,24 +431,3 @@ fn test_gen_fuzzy_crate_names() {
         &["DC__janus", "DC_-janus", "DC-_janus", "DC--janus"],
     );
 }
-
-fn summary_raw_path(crate_name: &str) -> String {
-    let crate_name = crate_name.to_ascii_lowercase();
-    match crate_name.len() {
-        0 => unreachable!("we check that crate_name is not empty here"),
-        1 => format!("1/{}", crate_name),
-        2 => format!("2/{}", crate_name),
-        3 => format!("3/{}/{}", &crate_name[..1], crate_name),
-        _ => format!("{}/{}/{}", &crate_name[..2], &crate_name[2..4], crate_name),
-    }
-}
-
-#[test]
-fn test_summary_raw_path() {
-    assert_eq!(summary_raw_path("a"), "1/a");
-    assert_eq!(summary_raw_path("ab"), "2/ab");
-    assert_eq!(summary_raw_path("abc"), "3/a/abc");
-    assert_eq!(summary_raw_path("abcd"), "ab/cd/abcd");
-    assert_eq!(summary_raw_path("abcdefg"), "ab/cd/abcdefg");
-    assert_eq!(summary_raw_path("Inflector"), "in/fl/inflector");
-}
diff --git a/src/registry.rs b/src/registry.rs
index 756f4555b2..bd3c367626 100644
--- a/src/registry.rs
+++ b/src/registry.rs
@@ -1,4 +1,3 @@
-use self::code_from_cargo::Kind;
 use crate::errors::*;
 use std::collections::HashMap;
 use std::path::{Path, PathBuf};
@@ -7,17 +6,6 @@ use url::Url;
 const CRATES_IO_INDEX: &str = "https://github.com/rust-lang/crates.io-index";
 const CRATES_IO_REGISTRY: &str = "crates-io";
 
-pub fn registry_path(manifest_path: &Path, registry: Option<&str>) -> Result<PathBuf> {
-    registry_path_from_url(&registry_url(manifest_path, registry)?)
-}
-
-pub fn registry_path_from_url(registry: &Url) -> Result<PathBuf> {
-    Ok(cargo_home()?
-        .join("registry")
-        .join("index")
-        .join(short_name(registry)))
-}
-
 #[derive(Debug, Deserialize)]
 struct Source {
     #[serde(rename = "replace-with")]
@@ -130,33 +118,6 @@ pub fn registry_url(manifest_path: &Path, registry: Option<&str>) -> Result<Url>
     Ok(registry_url)
 }
 
-fn short_name(registry: &Url) -> String {
-    // ref: https://github.com/rust-lang/cargo/blob/4c1fa54d10f58d69ac9ff55be68e1b1c25ecb816/src/cargo/sources/registry/mod.rs#L386-L390
-    #![allow(deprecated)]
-    use std::hash::{Hash, Hasher, SipHasher};
-
-    let mut hasher = SipHasher::new();
-    Kind::Registry.hash(&mut hasher);
-    registry.as_str().hash(&mut hasher);
-    let hash = hex::encode(hasher.finish().to_le_bytes());
-
-    let ident = registry.host_str().unwrap_or("").to_string();
-
-    format!("{}-{}", ident, hash)
-}
-
-#[cfg_attr(target_pointer_width = "64", test)]
-fn test_short_name() {
-    fn test_helper(url: &str, name: &str) {
-        let url = Url::parse(url).unwrap();
-        assert_eq!(short_name(&url), name);
-    }
-    test_helper(
-        "https://github.com/rust-lang/crates.io-index",
-        "github.com-1ecc6299db9ec823",
-    );
-}
-
 mod code_from_cargo {
     #![allow(dead_code)]