diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index 70820dce5f94..ae74016ad744 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -462,7 +462,7 @@ macro_rules! writeln {
 ///
 /// # Panics
 ///
-/// This will always panic.
+/// This will always [panic!](macro.panic.html)
 ///
 /// # Examples
 ///
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index 6eb9faacf7fb..6ad22820a7d9 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -24,6 +24,11 @@
 /// The multi-argument form of this macro panics with a string and has the
 /// `format!` syntax for building a string.
 ///
+/// # Current implementation
+///
+/// If the main thread panics it will terminate all your threads and end your
+/// program with code `101`.
+///
 /// # Examples
 ///
 /// ```should_panic