diff --git a/tests/by-util/test_cat.rs b/tests/by-util/test_cat.rs
index 26d929c82..64a511656 100644
--- a/tests/by-util/test_cat.rs
+++ b/tests/by-util/test_cat.rs
@@ -172,7 +172,7 @@ fn test_piped_to_dev_full() {
                 .set_stdout(dev_full)
                 .pipe_in_fixture("alpha.txt")
                 .fails()
-                .stderr_contains(&"No space left on device".to_owned());
+                .stderr_contains("No space left on device");
         }
     }
 }
diff --git a/tests/by-util/test_mv.rs b/tests/by-util/test_mv.rs
index 9fccc90a2..89f4043f8 100644
--- a/tests/by-util/test_mv.rs
+++ b/tests/by-util/test_mv.rs
@@ -263,7 +263,7 @@ fn test_mv_same_file_dot_dir() {
     ucmd.arg(".")
         .arg(".")
         .fails()
-        .stderr_is("mv: '.' and '.' are the same file\n".to_string());
+        .stderr_is("mv: '.' and '.' are the same file\n");
 }
 
 #[test]