diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index dd6e64057b444..0d7951bcfffc0 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -156,7 +156,6 @@ run-make/optimization-remarks-dir/Makefile
 run-make/output-filename-conflicts-with-directory/Makefile
 run-make/output-filename-overwrites-input/Makefile
 run-make/output-type-permutations/Makefile
-run-make/output-with-hyphens/Makefile
 run-make/override-aliased-flags/Makefile
 run-make/overwrite-input/Makefile
 run-make/panic-abort-eh_frame/Makefile
diff --git a/tests/run-make/output-with-hyphens/Makefile b/tests/run-make/output-with-hyphens/Makefile
deleted file mode 100644
index 846c9a66a89a0..0000000000000
--- a/tests/run-make/output-with-hyphens/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-
-all:
-	$(RUSTC) foo-bar.rs --crate-type bin
-	[ -f $(TMPDIR)/$(call BIN,foo-bar) ]
-	$(RUSTC) foo-bar.rs --crate-type lib
-	[ -f $(TMPDIR)/libfoo_bar.rlib ]
diff --git a/tests/run-make/output-with-hyphens/rmake.rs b/tests/run-make/output-with-hyphens/rmake.rs
new file mode 100644
index 0000000000000..21c003c628b9e
--- /dev/null
+++ b/tests/run-make/output-with-hyphens/rmake.rs
@@ -0,0 +1,17 @@
+// Rust files with hyphens in their filename should
+// not result in compiled libraries keeping that hyphen -
+// it should become an underscore. Only bin executables
+// should keep the hyphen. This test ensures that this rule
+// remains enforced.
+// See https://github.com/rust-lang/rust/pull/23786
+
+//@ ignore-cross-compile
+
+use run_make_support::{path, rustc};
+
+fn main() {
+    rustc().input("foo-bar.rs").crate_type("bin").run();
+    assert!(path(bin_name("foo-bar")).exists());
+    rustc().input("foo-bar.rs").crate_type("lib").run();
+    assert!(path(bin_name("libfoo_bar.rlib")).exists());
+}
diff --git a/tests/run-make/parallel-rustc-no-overwrite/rmake.rs b/tests/run-make/parallel-rustc-no-overwrite/rmake.rs
index d45eb4f29116e..40c6ab7ed5ebf 100644
--- a/tests/run-make/parallel-rustc-no-overwrite/rmake.rs
+++ b/tests/run-make/parallel-rustc-no-overwrite/rmake.rs
@@ -6,17 +6,19 @@
 // See https://github.com/rust-lang/rust/pull/83846
 
 use run_make_support::{fs_wrapper, rustc};
+use std::sync::{Arc, Barrier};
 use std::thread;
 
 fn main() {
-    fs_wrapper::create_file("lib.rs");
-    let handle1 = thread::spawn(move || {
-        rustc().crate_type("lib").arg("-Ztemps-dir=temp1").input("lib.rs");
-    });
-
-    let handle2 = thread::spawn(move || {
-        rustc().crate_type("staticlib").arg("-Ztemps-dir=temp2").input("lib.rs");
-    });
-    handle1.join().expect("lib thread panicked");
-    handle2.join().expect("staticlib thread panicked");
+    let barrier = Arc::new(Barrier::new(2));
+    let handle = {
+        let barrier = Arc::clone(&barrier);
+        thread::spawn(move || {
+            barrier.wait();
+            rustc().crate_type("lib").arg("-Ztemps-dir=temp1").input("lib.rs");
+        })
+    };
+    barrier.wait();
+    rustc().crate_type("staticlib").arg("-Ztemps-dir=temp2").input("lib.rs");
+    handle.join().expect("lib thread panicked");
 }