diff --git a/src/route-recognizer.js b/src/route-recognizer.js
index bae8e45..3a9fab9 100644
--- a/src/route-recognizer.js
+++ b/src/route-recognizer.js
@@ -238,7 +238,7 @@ function parse(route, names, types) {
   let results = [];
 
   let splitRoute = normalizedRoute.split('/');
-  for (let i = 0; i < splitRoute.length; i++) {
+  for (let i = 0, ii = splitRoute.length; i < ii; ++i) {
     let segment = splitRoute[i];
     let match = segment.match(/^:([^\/]+)$/);
     if (match) {
diff --git a/src/segments.js b/src/segments.js
index 03b83b4..1ff7281 100644
--- a/src/segments.js
+++ b/src/segments.js
@@ -28,8 +28,9 @@ export class StaticSegment {
   }
 
   eachChar(callback: (spec: CharSpec) => void): void {
-    for (let i = 0; i < this.string.length; i++) {
-      let ch = this.string[i];
+    let s = this.string;
+    for (let i = 0, ii = s.length; i < ii; ++i) {
+      let ch = s[i];
       callback({ validChars: ch });
     }
   }