diff --git a/graph-typed.rkt b/graph-typed.rkt
new file mode 100644
index 0000000..9942112
--- /dev/null
+++ b/graph-typed.rkt
@@ -0,0 +1,7 @@
+#lang typed/racket
+
+;;; Slap types on some graph functions.
+
+(require/typed/provide graph
+  [#:opaque Graph graph?]
+  [graphviz (-> Graph String)])