diff --git a/src/schema/objects/metadata.yaml b/src/schema/objects/metadata.yaml
index ea6e2fb5eb..0e1fe96916 100644
--- a/src/schema/objects/metadata.yaml
+++ b/src/schema/objects/metadata.yaml
@@ -500,6 +500,8 @@ ContrastBolusIngredient:
     - CARBON DIOXIDE
     - BARIUM
     - XENON
+    - UNKNOWN
+    - NONE
 DCOffsetCorrection:
   name: DCOffsetCorrection
   display_name: DC Offset Correction