--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -546,7 +546,7 @@ class RustBuild(object):
                 shutil.rmtree(bin_root)
 
             key = self.stage0_compiler.date
-            cache_dst = os.path.join(self.build_dir, "cache")
+            cache_dst = os.getenv('OPENWRT_RUSTC_BOOTSTRAP_CACHE', os.path.join(self.build_dir, "cache"))
             rustc_cache = os.path.join(cache_dst, key)
             if not os.path.exists(rustc_cache):
                 os.makedirs(rustc_cache)
--- a/src/bootstrap/download.rs
+++ b/src/bootstrap/download.rs
@@ -520,7 +520,10 @@ impl Config {
         key: &str,
         destination: &str,
     ) {
-        let cache_dst = self.out.join("cache");
+        let cache_dst = match env::var_os("OPENWRT_RUSTC_BOOTSTRAP_CACHE") {
+            Some(v) => PathBuf::from(v),
+            None => self.out.join("cache"),
+        };
         let cache_dir = cache_dst.join(key);
         if !cache_dir.exists() {
             t!(fs::create_dir_all(&cache_dir));
@@ -647,7 +650,10 @@ download-rustc = false
         let llvm_assertions = self.llvm_assertions;
 
         let cache_prefix = format!("llvm-{llvm_sha}-{llvm_assertions}");
-        let cache_dst = self.out.join("cache");
+        let cache_dst = match env::var_os("OPENWRT_RUSTC_BOOTSTRAP_CACHE") {
+            Some(v) => PathBuf::from(v),
+            None => self.out.join("cache"),
+        };
         let rustc_cache = cache_dst.join(cache_prefix);
         if !rustc_cache.exists() {
             t!(fs::create_dir_all(&rustc_cache));