diff --git a/README.md b/README.md
index 7621cfa..a722e60 100644
--- a/README.md
+++ b/README.md
@@ -68,10 +68,12 @@ features](http://doc.crates.io/manifest.html#the-features-section). They are:
   allows use of SQLite's online backup API.
 * [`functions`](http://jgallagher.github.io/rusqlite/rusqlite/functions/index.html)
   allows you to load Rust closures into SQLite connections for use in queries.
+  Note: This feature requires SQLite 3.8.3 or later.
 * [`trace`](http://jgallagher.github.io/rusqlite/rusqlite/trace/index.html)
   allows hooks into SQLite's tracing and profiling APIs.
 * [`blob`](http://jgallagher.github.io/rusqlite/rusqlite/blob/index.html)
-  gives `std::io::{Read, Write, Seek}` access to SQL BLOBs.
+  gives `std::io::{Read, Write, Seek}` access to SQL BLOBs. Note: This feature
+  requires SQLite 3.7.4 or later.
 * [`limits`](http://jgallagher.github.io/rusqlite/rusqlite/struct.Connection.html#method.limit)
   allows you to set and retrieve SQLite's per connection limits.
 * `chrono` implements [`FromSql`](http://jgallagher.github.io/rusqlite/rusqlite/types/trait.FromSql.html)