diff --git a/package.json b/package.json
index f04aca7..43230cc 100644
--- a/package.json
+++ b/package.json
@@ -77,7 +77,7 @@
     "clean-css": "^4.1.9",
     "debug": "^2.6.9",
     "dedupe": "^2.1.0",
-    "deepmerge": "^2.0.0",
+    "deepmerge": "^4.1.2",
     "html-minifier": "^3.5.5",
     "lru-cache": "^4.1.1",
     "no-case": "^2.3.2",