diff --git a/src/nodes/data.rs b/src/nodes/data.rs
index bf68058..74dee2c 100644
--- a/src/nodes/data.rs
+++ b/src/nodes/data.rs
@@ -24,7 +24,9 @@ pub fn mask_matches(mask_map_lesser: &Mask, mask_map_greater: &Mask) -> bool {
 		for key in mask_map_lesser.get_mask()?.iter_keys() {
 			let lesser_key = mask_map_lesser.get_mask()?.index(key)?;
 			let greater_key = mask_map_greater.get_mask()?.index(key)?;
-			if lesser_key.flexbuffer_type() != greater_key.flexbuffer_type() {
+			if !lesser_key.flexbuffer_type().is_null()
+				&& lesser_key.flexbuffer_type() != greater_key.flexbuffer_type()
+			{
 				return Err(flexbuffers::ReaderError::InvalidPackedType {}.into());
 			}
 		}