diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index 99000a031fea..5cb56433ac78 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -116,8 +116,9 @@ macro_rules! assert_eq {
         match (&$left, &$right) {
             (left_val, right_val) => {
                 if !(*left_val == *right_val) {
-                    panic!("assertion failed: `(left == right)` \
-                           (left: `{:?}`, right: `{:?}`)", left_val, right_val)
+                    panic!(r#"assertion failed: `(left == right)`
+left:  `{:?}`
+right: `{:?}`"#, left_val, right_val)
                 }
             }
         }
@@ -126,8 +127,9 @@ macro_rules! assert_eq {
         match (&($left), &($right)) {
             (left_val, right_val) => {
                 if !(*left_val == *right_val) {
-                    panic!("assertion failed: `(left == right)` \
-                           (left: `{:?}`, right: `{:?}`): {}", left_val, right_val,
+                    panic!(r#"assertion failed: `(left == right)`
+left:  `{:?}`
+right: `{:?}`: {}"#, left_val, right_val,
                            format_args!($($arg)+))
                 }
             }