diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 4b79b910ec39c..4abaf65726d61 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -246,7 +246,6 @@ run-make/rlib-format-packed-bundled-libs-3/Makefile
 run-make/rlib-format-packed-bundled-libs/Makefile
 run-make/rmeta-preferred/Makefile
 run-make/rustc-macro-dep-files/Makefile
-run-make/rustdoc-determinism/Makefile
 run-make/rustdoc-error-lines/Makefile
 run-make/rustdoc-io-error/Makefile
 run-make/rustdoc-map-file/Makefile
diff --git a/tests/run-make/rustdoc-determinism/Makefile b/tests/run-make/rustdoc-determinism/Makefile
deleted file mode 100644
index a3ef169067184..0000000000000
--- a/tests/run-make/rustdoc-determinism/Makefile
+++ /dev/null
@@ -1,16 +0,0 @@
-include ../tools.mk
-
-# Assert that the search index is generated deterministically, regardless of the
-# order that crates are documented in.
-
-# ignore-windows
-# Uses `diff`.
-
-all:
-	$(RUSTDOC) foo.rs -o $(TMPDIR)/foo_first
-	$(RUSTDOC) bar.rs -o $(TMPDIR)/foo_first
-
-	$(RUSTDOC) bar.rs -o $(TMPDIR)/bar_first
-	$(RUSTDOC) foo.rs -o $(TMPDIR)/bar_first
-
-	diff $(TMPDIR)/foo_first/search-index.js $(TMPDIR)/bar_first/search-index.js
diff --git a/tests/run-make/rustdoc-determinism/rmake.rs b/tests/run-make/rustdoc-determinism/rmake.rs
new file mode 100644
index 0000000000000..38ae75199fd83
--- /dev/null
+++ b/tests/run-make/rustdoc-determinism/rmake.rs
@@ -0,0 +1,18 @@
+use run_make_support::{diff, rustc, rustdoc, tmp_dir};
+
+/// Assert that the search index is generated deterministically, regardless of the
+/// order that crates are documented in.
+fn main() {
+    let dir_first = tmp_dir().join("first");
+    rustdoc().out_dir(&dir_first).input("foo.rs").run();
+    rustdoc().out_dir(&dir_first).input("bar.rs").run();
+
+    let dir_second = tmp_dir().join("second");
+    rustdoc().out_dir(&dir_second).input("bar.rs").run();
+    rustdoc().out_dir(&dir_second).input("foo.rs").run();
+
+    diff()
+        .expected_file(dir_first.join("search-index.js"))
+        .actual_file(dir_second.join("search-index.js"))
+        .run();
+}