diff --git a/src/math/rand/rand.go b/src/math/rand/rand.go
index d6422c914d87af..8179d9f4649a53 100644
--- a/src/math/rand/rand.go
+++ b/src/math/rand/rand.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package rand implements pseudo-random number generators.
+// Package rand implements pseudo-random number generators unsuitable for
+// security-sensitive work.
 //
 // Random numbers are generated by a Source. Top-level functions, such as
 // Float64 and Int, use a default shared Source that produces a deterministic
@@ -14,8 +15,9 @@
 // Mathematical interval notation such as [0, n) is used throughout the
 // documentation for this package.
 //
-// For random numbers suitable for security-sensitive work, see the crypto/rand
-// package.
+// This package's outputs might be easily predictable regardless of how it's
+// seeded. For random numbers suitable for security-sensitive work, see the
+// crypto/rand package.
 package rand
 
 import "sync"