diff --git a/tests/run-pass/aligned_utf8_check.rs b/tests/run-pass/aligned_utf8_check.rs
index 0d2b2bf66a..202856b3bd 100644
--- a/tests/run-pass/aligned_utf8_check.rs
+++ b/tests/run-pass/aligned_utf8_check.rs
@@ -6,7 +6,7 @@ fn main() {
     let mut y: Vec<u8> = unsafe { std::mem::transmute(x) };
     unsafe { y.set_len(2 * N) };
 
-    println!("{:?}", String::from_utf8_lossy(&y));
+    println!("{:?}", std::str::from_utf8(&y).unwrap());
 
     let mut x: Vec<u16> = unsafe { std::mem::transmute(y) };
     unsafe { x.set_len(N) };