diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index f4c101cf81c..487132683e9 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -387,7 +387,7 @@ pub fn recursive_diff(dir1: impl AsRef<Path>, dir2: impl AsRef<Path>) {
     });
 }
 
-pub fn read_dir<F: Fn(&Path)>(dir: impl AsRef<Path>, callback: F) {
+pub fn read_dir<F: FnMut(&Path)>(dir: impl AsRef<Path>, mut callback: F) {
     for entry in fs_wrapper::read_dir(dir) {
         callback(&entry.unwrap().path());
     }
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index 970a424d998..c3a94d17cd9 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -52,7 +52,6 @@ run-make/foreign-rust-exceptions/Makefile
 run-make/include_bytes_deps/Makefile
 run-make/incr-add-rust-src-component/Makefile
 run-make/incr-foreign-head-span/Makefile
-run-make/inline-always-many-cgu/Makefile
 run-make/interdependent-c-libraries/Makefile
 run-make/intrinsic-unreachable/Makefile
 run-make/invalid-library/Makefile
diff --git a/tests/run-make/inline-always-many-cgu/Makefile b/tests/run-make/inline-always-many-cgu/Makefile
deleted file mode 100644
index 9945821db28..00000000000
--- a/tests/run-make/inline-always-many-cgu/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-include ../tools.mk
-
-all:
-	$(RUSTC) foo.rs --emit llvm-ir -C codegen-units=2
-	if cat $(TMPDIR)/*.ll | $(CGREP) -e '\bcall\b'; then \
-		echo "found call instruction when one wasn't expected"; \
-		exit 1; \
-	fi
diff --git a/tests/run-make/inline-always-many-cgu/rmake.rs b/tests/run-make/inline-always-many-cgu/rmake.rs
new file mode 100644
index 00000000000..c55ea69f3b9
--- /dev/null
+++ b/tests/run-make/inline-always-many-cgu/rmake.rs
@@ -0,0 +1,18 @@
+use run_make_support::fs_wrapper::read_to_string;
+use run_make_support::regex::Regex;
+use run_make_support::{read_dir, rustc};
+
+use std::ffi::OsStr;
+
+fn main() {
+    rustc().input("foo.rs").emit("llvm-ir").codegen_units(2).run();
+    let re = Regex::new(r"\bcall\b").unwrap();
+    let mut nb_ll = 0;
+    read_dir(".", |path| {
+        if path.is_file() && path.extension().is_some_and(|ext| ext == OsStr::new("ll")) {
+            assert!(!re.is_match(&read_to_string(path)));
+            nb_ll += 1;
+        }
+    });
+    assert!(nb_ll > 0);
+}