diff --git a/pkgs/clan-cli/clan_cli/nix/__init__.py b/pkgs/clan-cli/clan_cli/nix/__init__.py
index 9a54f960c..6ac7243ac 100644
--- a/pkgs/clan-cli/clan_cli/nix/__init__.py
+++ b/pkgs/clan-cli/clan_cli/nix/__init__.py
@@ -44,8 +44,9 @@ def nix_build(flags: list[str], gcroot: Path | None = None) -> list[str]:
 
 
 def nix_add_to_gcroots(nix_path: Path, dest: Path) -> None:
-    cmd = ["nix-store", "--realise", f"{nix_path}", "--add-root", f"{dest}"]
-    run(cmd)
+    if not os.environ.get("IN_NIX_SANDBOX"):
+        cmd = ["nix-store", "--realise", f"{nix_path}", "--add-root", f"{dest}"]
+        run(cmd)
 
 
 def nix_config() -> dict[str, Any]: