diff --git a/sankey/sankey.js b/sankey/sankey.js
index c3bc59f..abe137b 100644
--- a/sankey/sankey.js
+++ b/sankey/sankey.js
@@ -118,7 +118,9 @@ d3.sankey = function() {
         node.x = x;
         node.dx = nodeWidth;
         node.sourceLinks.forEach(function(link) {
-          nextNodes.push(link.target);
+          if (nextNodes.indexOf(link.target) < 0) {
+            nextNodes.push(link.target);
+          }
         });
       });
       remainingNodes = nextNodes;