diff --git a/taxonomylib/taxonomylib.py b/taxonomylib/taxonomylib.py
index 1e172e28ff5cd84e58b9536f6191f1059e48f277..33639609d0adaf6812eee462434f1126347decec 100644
--- a/taxonomylib/taxonomylib.py
+++ b/taxonomylib/taxonomylib.py
@@ -62,6 +62,7 @@ taxonomy_ids = {
     "CR": "material",
     "CIP": "material",
     "CBH": "material",
+    "E": "material",
     "EU": "material",
     "ER": "material",
     "MCF": "material",