diff --git a/src/primitives/array.md b/src/primitives/array.md
index 9cec24d699..5f5e699445 100644
--- a/src/primitives/array.md
+++ b/src/primitives/array.md
@@ -63,7 +63,9 @@ fn main() {
         }
     }
 
-    // Out of bound indexing causes compile time error.
+    // Out of bound indexing on array causes compile time error.
     //println!("{}", xs[5]);
+    // Out of bound indexing on slice causes runtime error.
+    //println!("{}", xs[..][5]);
 }
 ```