diff --git a/package.json b/package.json
index ce226dc0..dc6dabcb 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
   },
   "homepage": "https://github.com/Munter/subfont#readme",
   "dependencies": {
-    "assetgraph": "^4.7.2",
+    "assetgraph": "github:assetgraph/assetgraph#feature/traceCustomCssProperties",
     "urltools": "^0.3.5",
     "yargs": "^11.0.0"
   },