diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index 9b4c7c91349..876ee8be151 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -682,6 +682,8 @@ fn run(self, builder: &Builder<'_>) {
         let mut cargo = tool::prepare_tool_cargo(
             builder,
             compiler,
+            // compiletest uses libtest internals; make it use the in-tree std to make sure it never breaks
+            // when std sources change.
             Mode::ToolStd,
             host,
             "test",
@@ -1321,13 +1323,12 @@ fn make_run(run: RunConfig<'_>) {
     /// Runs `cargo test` for run-make-support.
     fn run(self, builder: &Builder<'_>) {
         let host = self.host;
-        let compiler = builder.compiler(builder.top_stage, host);
+        let compiler = builder.compiler(0, host);
 
-        builder.ensure(compile::Std::new(compiler, host));
         let mut cargo = tool::prepare_tool_cargo(
             builder,
             compiler,
-            Mode::ToolStd,
+            Mode::ToolBootstrap,
             host,
             "test",
             "src/tools/run-make-support",