diff --git a/Cargo.lock b/Cargo.lock
index 790d2b37..349ca717 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -531,9 +531,9 @@ dependencies = [
 
 [[package]]
 name = "once_cell"
-version = "1.16.0"
+version = "1.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
+checksum = "2f7254b99e31cad77da24b08ebf628882739a608578bb1bcdfc1f9c21260d7c0"
 
 [[package]]
 name = "openssl-probe"
@@ -701,6 +701,7 @@ dependencies = [
  "flate2",
  "git2",
  "indexmap",
+ "once_cell",
  "serde",
  "serde_json",
  "strsim",
diff --git a/Cargo.toml b/Cargo.toml
index a0137855..370d6b08 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -40,6 +40,7 @@ strsim = "0.10"
 tempfile = "3"
 termcolor = "1.1"
 thiserror = "~1.0"
+once_cell = "~1.14"
 
 bzip2 = { version = "0.4", optional = true }
 curl = { version = "0.4", optional = true }
@@ -47,6 +48,7 @@ flate2 = { version = "1", optional = true }
 tar = { version = "0.4", optional = true }
 
 [features]
-default = ["import-compressed", "import-url"]
+default = ["import-compressed", "import-url", "git2-ext-worktreeconfig-support"]
 import-compressed = ["dep:bzip2", "dep:flate2", "dep:tar"]
 import-url = ["dep:curl"]
+git2-ext-worktreeconfig-support = []
diff --git a/src/main.rs b/src/main.rs
index c9ed8639..ee76768b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -42,6 +42,34 @@ const COMMAND_ERROR: i32 = 2;
 /// Process exit code for when a command halts due to merge conflicts.
 const CONFLICT_ERROR: i32 = 3;
 
+/// Initialize [`git2`] library.
+///
+/// [`git2`] library by default fails any operation if it encounters any extensions configured in a repo.
+/// [`stg`] is using [`git2`] library as an interface to object database and for looking alias lookup from git configuration.
+///
+/// As a workaround until `worktreeconfig` extension is supported upstream, add it to whitelisted extensions.
+///
+/// # Safety
+/// * Modifying whitelisted extensions in [`git2`] is like modifying a static mut variable (unsafe).
+/// * This function must be called at initialization time (before git2 library usage) and should be called only once.
+unsafe fn init_libgit2() -> Result<()> {
+    if cfg!(feature = "git2-ext-worktreeconfig-support") {
+        return git2::opts::set_extensions(&["worktreeconfig"])
+            .context("Failed to set worktreeconfig extension");
+    }
+    Ok(())
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_me() {
+        unsafe { init_libgit2() }.expect("success");
+    }
+}
+
 /// Create base [`clap::Command`] instance.
 ///
 /// The base [`clap::Command`] returned by this function is intended to be supplemented
@@ -138,6 +166,9 @@ pub(crate) fn get_full_command(
 /// The name of the game is to dispatch to the appropriate subcommand or alias as
 /// quickly as possible.
 fn main() -> ! {
+    // Initialize git2 library.
+    unsafe { init_libgit2() }.expect("Failed libgit2 init");
+
     let argv: Vec<OsString> = std::env::args_os().collect();
 
     // Chicken and egg: the --color option must be parsed from argv in order to setup