diff --git a/Cargo.lock b/Cargo.lock
index 6f7a88f6a..01bfbdc4b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -47,6 +47,16 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
 
+[[package]]
+name = "backoff"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "721c249ab59cbc483ad4294c9ee2671835c1e43e9ffc277e6b4ecfef733cfdc5"
+dependencies = [
+ "instant",
+ "rand 0.7.3",
+]
+
 [[package]]
 name = "base64"
 version = "0.12.3"
@@ -168,6 +178,12 @@ version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "chrono"
 version = "0.4.19"
@@ -282,7 +298,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "058ed274caafc1f60c4997b5fc07bf7dc7cca454af7c6e81edffe5f33f70dace"
 dependencies = [
  "autocfg",
- "cfg-if",
+ "cfg-if 0.1.10",
  "crossbeam-utils",
  "lazy_static",
  "maybe-uninit",
@@ -297,7 +313,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3c7c73a2d1e9fc0886a08b93e98eb643461230d5f1925e4036204d5f2e261a8"
 dependencies = [
  "autocfg",
- "cfg-if",
+ "cfg-if 0.1.10",
  "lazy_static",
 ]
 
@@ -414,7 +430,7 @@ version = "0.1.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc587bc0ec293155d5bfa6b9891ec18a1e330c234f896ea47fbada4cadbe47e6"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "wasi 0.9.0+wasi-snapshot-preview1",
 ]
@@ -425,7 +441,7 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ee8025cf36f917e6a52cce185b7c7177689b838b7ec138364e50cc2277a56cf4"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "wasi 0.9.0+wasi-snapshot-preview1",
 ]
@@ -492,6 +508,15 @@ dependencies = [
  "unindent",
 ]
 
+[[package]]
+name = "instant"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61124eeebbd69b8190558df225adf7e4caafce0d743919e5d6b19652314ec5ec"
+dependencies = [
+ "cfg-if 1.0.0",
+]
+
 [[package]]
 name = "itertools"
 version = "0.9.0"
@@ -539,6 +564,7 @@ dependencies = [
 name = "jj-lib"
 version = "0.1.0"
 dependencies = [
+ "backoff",
  "blake2",
  "byteorder",
  "bytes 1.0.0",
@@ -593,7 +619,7 @@ checksum = "db65c6da02e61f55dae90a0ae427b2a5f6b3e8db09f58d10efab23af92592616"
 dependencies = [
  "arrayvec",
  "bitflags",
- "cfg-if",
+ "cfg-if 0.1.10",
  "ryu",
  "static_assertions",
 ]
@@ -666,7 +692,7 @@ version = "0.4.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4fabed175da42fed1fa0746b0ea71f412aa9d35e76e95e59b192c64b9dc2bf8b"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
 ]
 
 [[package]]
@@ -1242,7 +1268,7 @@ version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7a6e24d9338a0a5be79593e2fa15a648add6138caa803e2d5bc782c371732ca9"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "libc",
  "rand 0.7.3",
  "redox_syscall",
@@ -1451,7 +1477,7 @@ version = "0.2.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ac64ead5ea5f05873d7c12b545865ca2b8d28adfc50a49b84770a3a97265d42"
 dependencies = [
- "cfg-if",
+ "cfg-if 0.1.10",
  "wasm-bindgen-macro",
 ]
 
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index fc1d585b5..f7db59dfc 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -10,6 +10,7 @@ edition = "2018"
 protobuf-codegen-pure = "2.18.1"
 
 [dependencies]
+backoff = "0.2.1"
 blake2 = "0.9.1"
 bytes = "1.0.0"
 byteorder = "1.3.4"
diff --git a/lib/src/git_store.rs b/lib/src/git_store.rs
index 4eef16093..e49e5c61c 100644
--- a/lib/src/git_store.rs
+++ b/lib/src/git_store.rs
@@ -27,6 +27,7 @@ use crate::store::{
     ChangeId, Commit, CommitId, Conflict, ConflictId, ConflictPart, FileId, MillisSinceEpoch,
     Signature, Store, StoreError, StoreResult, SymlinkId, Timestamp, Tree, TreeId, TreeValue,
 };
+use backoff::{ExponentialBackoff, Operation};
 
 const NOTES_REF: &str = "refs/notes/jj/commits";
 const NOTES_REF_LOCK: &str = "refs/notes/jj/commits.lock";
@@ -316,7 +317,10 @@ impl Store for GitStore {
         // TODO: Include the extra commit data in commit headers instead of a ref.
         // Unfortunately, it doesn't seem like libgit2-rs supports that. Perhaps
         // we'll have to serialize/deserialize the commit data ourselves.
-        loop {
+        // It seems that libgit2 doesn't retry when .git/refs/notes/jj/commits.lock
+        // already exists, so we do the retrying ourselves.
+        // TODO: Report this to libgit2.
+        let mut try_write_note = || {
             let note_status = locked_repo.note(
                 &committer,
                 &committer,
@@ -327,20 +331,21 @@ impl Store for GitStore {
             );
             match note_status {
                 Err(err) if err.message().contains(NOTES_REF_LOCK) => {
-                    // It seems that libgit2 doesn't retry when .git/refs/notes/jj/commits.lock
-                    // already exists.
-                    // TODO: Report this to libgit2.
-                    let retry_delay = Duration::from_millis(10);
-                    std::thread::sleep(retry_delay);
-                }
-                Err(err) => {
-                    return Err(StoreError::from(err));
-                }
-                Ok(_) => {
-                    break;
+                    Err(backoff::Error::Transient(err))
                 }
+                Err(err) => Err(backoff::Error::Permanent(err)),
+                Ok(_) => Ok(()),
             }
-        }
+        };
+        let mut backoff = ExponentialBackoff::default();
+        backoff.initial_interval = Duration::from_millis(1);
+        backoff.max_elapsed_time = Some(Duration::from_secs(10));
+        try_write_note
+            .retry(&mut backoff)
+            .map_err(|err| match err {
+                backoff::Error::Permanent(err) => err,
+                backoff::Error::Transient(err) => err,
+            })?;
 
         Ok(id)
     }