diff --git a/miniKanren.scm b/miniKanren.scm
index 17c81b2..f960aad 100644
--- a/miniKanren.scm
+++ b/miniKanren.scm
@@ -1,6 +1,7 @@
 ;; In order to use "basic" miniKanren
 
 (load "ck.scm")
+(load "tree-unify.scm")
 
 (define-syntax run1 (syntax-rules () ((_ (x) g0 g ...) (run 1 (x) g0 g ...))))
 (define-syntax run2 (syntax-rules () ((_ (x) g0 g ...) (run 2 (x) g0 g ...))))