diff --git a/src/tools/run-make-support/src/command.rs b/src/tools/run-make-support/src/command.rs
index 0a1bd9b0b34..ee651704c6f 100644
--- a/src/tools/run-make-support/src/command.rs
+++ b/src/tools/run-make-support/src/command.rs
@@ -185,14 +185,14 @@ pub fn assert_stdout_equals<S: AsRef<str>>(&self, expected: S) -> &Self {
     /// Checks that `stdout` does not contain `unexpected`.
     #[track_caller]
     pub fn assert_stdout_not_contains<S: AsRef<str>>(&self, unexpected: S) -> &Self {
-        assert_not_contains(&self.stdout_utf8(), unexpected.as_ref());
+        assert_not_contains(&self.stdout_utf8(), unexpected);
         self
     }
 
     /// Checks that `stdout` contains `expected`.
     #[track_caller]
     pub fn assert_stdout_contains<S: AsRef<str>>(&self, expected: S) -> &Self {
-        assert_contains(&self.stdout_utf8(), expected.as_ref());
+        assert_contains(&self.stdout_utf8(), expected);
         self
     }
 
@@ -206,14 +206,14 @@ pub fn assert_stderr_equals<S: AsRef<str>>(&self, expected: S) -> &Self {
     /// Checks that `stderr` contains `expected`.
     #[track_caller]
     pub fn assert_stderr_contains<S: AsRef<str>>(&self, expected: S) -> &Self {
-        assert_contains(&self.stderr_utf8(), expected.as_ref());
+        assert_contains(&self.stderr_utf8(), expected);
         self
     }
 
     /// Checks that `stderr` does not contain `unexpected`.
     #[track_caller]
     pub fn assert_stderr_not_contains<S: AsRef<str>>(&self, unexpected: S) -> &Self {
-        assert_not_contains(&self.stdout_utf8(), unexpected.as_ref());
+        assert_not_contains(&self.stdout_utf8(), unexpected);
         self
     }
 
diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index df417722e02..294dae10942 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -409,7 +409,9 @@ pub fn read_dir<F: FnMut(&Path)>(dir: impl AsRef<Path>, mut callback: F) {
 
 /// Check that `actual` is equal to `expected`. Panic otherwise.
 #[track_caller]
-pub fn assert_equals(actual: &str, expected: &str) {
+pub fn assert_equals<S1: AsRef<str>, S2: AsRef<str>>(actual: S1, expected: S2) {
+    let actual = actual.as_ref();
+    let expected = expected.as_ref();
     if actual != expected {
         eprintln!("=== ACTUAL TEXT ===");
         eprintln!("{}", actual);
@@ -421,7 +423,9 @@ pub fn assert_equals(actual: &str, expected: &str) {
 
 /// Check that `haystack` contains `needle`. Panic otherwise.
 #[track_caller]
-pub fn assert_contains(haystack: &str, needle: &str) {
+pub fn assert_contains<S1: AsRef<str>, S2: AsRef<str>>(haystack: S1, needle: S2) {
+    let haystack = haystack.as_ref();
+    let needle = needle.as_ref();
     if !haystack.contains(needle) {
         eprintln!("=== HAYSTACK ===");
         eprintln!("{}", haystack);
@@ -433,7 +437,9 @@ pub fn assert_contains(haystack: &str, needle: &str) {
 
 /// Check that `haystack` does not contain `needle`. Panic otherwise.
 #[track_caller]
-pub fn assert_not_contains(haystack: &str, needle: &str) {
+pub fn assert_not_contains<S1: AsRef<str>, S2: AsRef<str>>(haystack: S1, needle: S2) {
+    let haystack = haystack.as_ref();
+    let needle = needle.as_ref();
     if haystack.contains(needle) {
         eprintln!("=== HAYSTACK ===");
         eprintln!("{}", haystack);
diff --git a/tests/run-make/compressed-debuginfo/rmake.rs b/tests/run-make/compressed-debuginfo/rmake.rs
index 9c6d50ab243..58eb2d6b1b3 100644
--- a/tests/run-make/compressed-debuginfo/rmake.rs
+++ b/tests/run-make/compressed-debuginfo/rmake.rs
@@ -23,8 +23,8 @@ fn check_compression(compression: &str, to_find: &str) {
             cmd("readelf").arg("-t").arg("foo.o").run().assert_stdout_contains(to_find);
         } else {
             assert_contains(
-                &stderr,
-                &format!("unknown debuginfo compression algorithm {compression}"),
+                stderr,
+                format!("unknown debuginfo compression algorithm {compression}"),
             );
         }
     });