diff --git a/README.rst b/README.rst
index e7d4517..c00654f 100644
--- a/README.rst
+++ b/README.rst
@@ -2,7 +2,7 @@
 arrayvec
 ========
 
-A vector with fixed capacity.
+A vector with fixed capacity.  Requires Rust 1.2+.
 
 Please read the `API documentation here`__