diff --git a/ossdbs/utils/materials.py b/ossdbs/utils/materials.py
index 8b6f39b3..6a7f4f4f 100644
--- a/ossdbs/utils/materials.py
+++ b/ossdbs/utils/materials.py
@@ -1 +1 @@
-MATERIALS = {"Blood": 4, "Gray matter": 3, "White matter": 2, "CSF": 1, "Unknown": 0}
+MATERIALS = {"Blood": 4, "Gray matter": 1, "White matter": 2, "CSF": 3, "Unknown": 0}