diff --git a/lib/source-map-cache.js b/lib/source-map-cache.js
index df4d16f85..e554bace7 100644
--- a/lib/source-map-cache.js
+++ b/lib/source-map-cache.js
@@ -76,7 +76,10 @@ SourceMapCache.prototype._rewritePath = function (report, fileReport, sourceMap)
   if (sourceMap.sources.length !== 1) return
 
   var originalPath = './' + path.join(path.dirname(fileReport.path), sourceMap.sources[0])
+
+  report[fileReport.path] = undefined // Hack for Windows tests, until we can normalize paths.
   delete report[fileReport.path]
+
   fileReport.path = originalPath
   report[originalPath] = fileReport
 }
diff --git a/package.json b/package.json
index 3af27f127..82e331b6d 100644
--- a/package.json
+++ b/package.json
@@ -81,7 +81,7 @@
     "yargs": "^3.15.0"
   },
   "devDependencies": {
-    "any-path": "^1.2.0",
+    "any-path": "^1.3.0",
     "chai": "^3.0.0",
     "coveralls": "^2.11.4",
     "del": "^2.2.0",
diff --git a/test/src/source-map-cache.js b/test/src/source-map-cache.js
index 520e2131c..3216310a6 100644
--- a/test/src/source-map-cache.js
+++ b/test/src/source-map-cache.js
@@ -2,6 +2,7 @@
 
 var _ = require('lodash')
 var ap = require('any-path')
+var expect = require('chai').expect
 var path = require('path')
 
 var convertSourceMap = require('convert-source-map')
@@ -68,13 +69,13 @@ describe('source-map-cache', function () {
     it('does not rewrite path if the source map has more than one source', function () {
       var report = getReport()
       sourceMapCache.applySourceMaps(report)
-      report.should.have.property(covered.bundle.relpath)
+      expect(report[covered.bundle.relpath]).to.not.equal(undefined)
     })
 
-    it('rewrites path if the source map exactly one source', function () {
-      var report = _.pick(getReport(), fixture.relpath)
+    it('rewrites path if the source map has exactly one source', function () {
+      var report = ap(_.pick(getReport(), fixture.relpath))
       sourceMapCache.applySourceMaps(report)
-      report.should.not.have.property(fixture.relpath)
+      expect(report[fixture.relpath]).to.equal(undefined)
       report.should.have.property(fixture.mappedPath)
     })
   })