diff --git a/package.json b/package.json
index a9350d5..93037f7 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,7 @@
     "karma-coveralls": "^1.1.2",
     "karma-jasmine": "^1.1.0",
     "karma-mocha-reporter": "^2.2.1",
-    "karma-scss-preprocessor": "^3.0.0",
+    "karma-scss-preprocessor": "^4.0.0",
     "karma-typescript": "^3.0.0",
     "matchdep": "^2.0.0",
     "node-sass": "^4.1.1",