Fix typo in explaining of shorthand types
diff --git a/src/lib.rs b/src/lib.rs
index aaaa566..0ecef81 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -85,7 +85,7 @@
//!
//! Each graph type vends a few shorthand type definitions that name some specific
//! generic choices. For example, [`DiGraph<_, _>`](./graph/type.DiGraph.html) is shorthand
-//! for [`Graph<_, _, Undirected>`](graph/struct.Graph.html).
+//! for [`Graph<_, _, Directed>`](graph/struct.Graph.html).
//! [`UnMatrix<_, _>`](./matrix_graph/type.UnMatrix.html) is shorthand for
//! [`MatrixGraph<_, _, Undirected>`](./matrix_graph/struct.MatrixGraph.html). Each graph type's
//! module documentation lists the available shorthand types.
