diff --git a/Cargo.lock b/Cargo.lock
index b45efa5..6d50eeb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -125,7 +125,7 @@ checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
 [[package]]
 name = "codex-apply-patch"
 version = "0.0.0"
-source = "git+https://github.com/openai/codex.git?branch=main#325fad1d92cba5e5925459ca9799ccb000fde6d8"
+source = "git+https://github.com/openai/codex.git?rev=a23c1949727a72dbed0c630048a5a1a353eb9168#a23c1949727a72dbed0c630048a5a1a353eb9168"
 dependencies = [
  "anyhow",
  "similar",
diff --git a/Cargo.toml b/Cargo.toml
index c9066cf..e311618 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,7 +4,8 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-codex-apply-patch = { git = "https://github.com/openai/codex.git", package = "codex-apply-patch", branch = "main" }
+# Pin to a stable commit (tag rust-v0.43.0) to avoid drift from main and improve reproducibility
+codex-apply-patch = { git = "https://github.com/openai/codex.git", package = "codex-apply-patch", rev = "a23c1949727a72dbed0c630048a5a1a353eb9168" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 log = "0.4"