diff --git a/README b/README
index 172c1a5..04a25d8 100644
--- a/README
+++ b/README
@@ -27,7 +27,7 @@ Usage
 Dependencies
 ------------
 
-   Rust 1.33 or later is required to build.
+   Rust 1.40 or later is required to build.
 
 Specifications
 --------------