diff --git a/src/adjacent_exchange.js b/src/adjacent_exchange.js
index 9fc3cfd..abf9193 100644
--- a/src/adjacent_exchange.js
+++ b/src/adjacent_exchange.js
@@ -1,3 +1,5 @@
+import { inverse_permutation } from './permutation';
+
 // Accorging to
 // E. R. Gansner, E. Koutsofios, S. C. North, and K.-P. Vo. 1993. A
 // Technique for Drawing Directed Graphs. IEEE Trans. Softw. Eng. 19, 3
diff --git a/src/barycenter_order.js b/src/barycenter_order.js
index 3e01d09..f7ebe40 100644
--- a/src/barycenter_order.js
+++ b/src/barycenter_order.js
@@ -1,6 +1,7 @@
 import { cmp_number } from './utils';
 import { inverse_permutation } from './permutation';
 import { debug } from './core';
+import { count_crossings } from './count_crossings';
 
 export function barycenter_order(graph, comps, max_iter) {
     var orders = [[], [], 0];
diff --git a/src/index.js b/src/index.js
index 8c459ba..da2605e 100644
--- a/src/index.js
+++ b/src/index.js
@@ -1,3 +1,4 @@
+export { adjacent_exchange } from './adjacent_exchange';
 export { zeroes, dot, length, normalize, mean, transpose } from './aliases';
 export {
   all_pairs_distance,