diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 3b8c3655b8d1c..d4b5a80921508 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1832,7 +1832,9 @@ impl Config {
                 .join(exe("rustc", config.build))
         };
 
-        config.initial_sysroot = config.initial_rustc.ancestors().nth(2).unwrap().into();
+        config.initial_sysroot = t!(PathBuf::from_str(
+            output(Command::new(&config.initial_rustc).args(["--print", "sysroot"])).trim()
+        ));
 
         config.initial_cargo_clippy = cargo_clippy;