diff --git a/lib/Host.js b/lib/Host.js
index fe9f2d7..7f1d3b6 100644
--- a/lib/Host.js
+++ b/lib/Host.js
@@ -104,7 +104,7 @@ module.exports = function (ts) {
 	Host.prototype.getDefaultLibFileName = function () {
 		var libPath = path.dirname(ts.sys.getExecutingFilePath());
 		var libFile = ts.getDefaultLibFileName({ target: this.languageVersion });
-		return path.join(libPath, libFile);
+		return ts.normalizeSlashes(path.join(libPath, libFile));
 	};
 
 	Host.prototype.writeFile = function (filename, data) {