diff --git a/data/fields/material.json b/data/fields/material.json
index 5310bde6c..c80040b80 100644
--- a/data/fields/material.json
+++ b/data/fields/material.json
@@ -11,7 +11,7 @@
             "bronze": "Bronze",
             "concrete": "Concrete",
             "dry_stone": "Dry Stone",
-            "glas": "Glas",
+            "glass": "Glass",
             "granite": "Granite",
             "iron": "Iron",
             "limestone": "Limestone",