diff --git a/src/graph2mat.js b/src/graph2mat.js
index 2478796..c960cac 100644
--- a/src/graph2mat.js
+++ b/src/graph2mat.js
@@ -4,38 +4,37 @@ export function graph2mat(graph, directed) {
   const nodes = graph.nodes();
   const links = graph.links();
   const n = nodes.length;
-  let i;
-  let l;
   let mat;
 
   if (!directed) directed = graph.directed();
   if (directed) {
-    let rows = n,
-      cols = n;
+    let rows = n;
+    let cols = n;
 
-    for (i = n - 1; i >= 0; i--) {
+    for (let i = n - 1; i >= 0; i--) {
       if (graph.inEdges(i).length !== 0) break;
       else rows--;
     }
-    for (i = n - 1; i >= 0; i--) {
+    for (let i = n - 1; i >= 0; i--) {
       if (graph.outEdges(i).length !== 0) break;
       else cols--;
     }
     //console.log("Rows: "+rows+" Cols: "+cols);
     mat = zeroes(rows, cols);
 
-    for (i = 0; i < links.length; i++) {
-      l = links[i];
+    for (let i = 0; i < links.length; i++) {
+      const l = links[i];
       mat[l.source.index][l.target.index] = l.value ? l.value : 1;
     }
   } else {
     mat = zeroes(n, n);
 
-    for (i = 0; i < links.length; i++) {
-      l = links[i];
+    for (let i = 0; i < links.length; i++) {
+      const l = links[i];
       mat[l.source.index][l.target.index] = l.value ? l.value : 1;
       mat[l.target.index][l.source.index] = l.value ? l.value : 1;
     }
   }
+
   return mat;
 }