diff --git a/packages/material-ui/package.json b/packages/material-ui/package.json
index f00724b99880f1..ae9c06bdbf6fd6 100644
--- a/packages/material-ui/package.json
+++ b/packages/material-ui/package.json
@@ -68,6 +68,7 @@
     "@popperjs/core": "^2.4.4",
     "@types/react-transition-group": "^4.2.0",
     "clsx": "^1.0.4",
+    "csstype": "^3.0.2",
     "hoist-non-react-statics": "^3.3.2",
     "prop-types": "^15.7.2",
     "react-is": "^16.8.0",