diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index db47efa9670..c753f7ff42d 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -459,16 +459,18 @@ module ts {
             if (path.charCodeAt(2) === CharacterCodes.slash) return 3;
             return 2;
         }
-        // Per RFC 1738'file' URI schema has a shape file://<host>/<path>
-        // if <host> is omitted then it is assumed that host value is'localhost',
+        // Per RFC 1738 'file' URI schema has the shape file://<host>/<path>
+        // if <host> is omitted then it is assumed that host value is 'localhost',
         // however slash after the omitted <host> is not removed.
-        // file:///folder1/file1 - this is correct URI
-        // file://folder2/file2 - this is incorrect URI
+        // file:///folder1/file1 - this is a correct URI
+        // file://folder2/file2 - this is an incorrect URI
         if (path.lastIndexOf("file:///", 0) === 0) {
             return "file:///".length;
         }
         let idx = path.indexOf('://');
-        if (idx !== -1) return idx + 3
+        if (idx !== -1) {
+            return idx + "://".length;
+        }
         return 0;
     }