diff --git a/packages/playground/package.json b/packages/playground/package.json
index 84882a0e..c4e0ba1d 100644
--- a/packages/playground/package.json
+++ b/packages/playground/package.json
@@ -22,7 +22,7 @@
     "gh-pages": "3.2.3",
     "jstat": "1.9.5",
     "lenses-ppx": "6.1.10",
-    "less": "3.10.3",
+    "less": "4.1.2",
     "lodash": "4.17.21",
     "mathjs": "10.4.1",
     "moduleserve": "0.9.1",