diff --git a/server/dataset/termdb.test.ts b/server/dataset/termdb.test.ts
index edb5deff50..dc460a70e4 100644
--- a/server/dataset/termdb.test.ts
+++ b/server/dataset/termdb.test.ts
@@ -261,8 +261,8 @@ export default function (): Mds3 {
 					},
 					{
 						name: 'Assay Availability',
-						//keys: ['yes'],
 						type: 'categorical',
+						categoryKeys: ['1'],
 						termIds: ['assayavailability_cnv', 'assayavailability_fusion', 'assayavailability_germline'],
 						branchIds: [''],
 						propsByTermId: {}
diff --git a/shared/types/src/dataset.ts b/shared/types/src/dataset.ts
index c61ae23f2b..388e3a427e 100644
--- a/shared/types/src/dataset.ts
+++ b/shared/types/src/dataset.ts
@@ -1619,17 +1619,9 @@ keep this setting here for reason of:
 	termCollections?: TermCollection[]
 }
 
-type TermCollection = {
+type TermCollectionBase = {
 	/** human readable name as well as unique identifier for this collection */
 	name: string
-	/** collection term type.
-	numeric:
-	- all member terms must be either integer or float type
-	categorical:
-	- all member terms must be categorical terms with same set of categories
-	*/
-	type: 'numeric' | 'categorical'
-	// TODO: add categoryKey field for categorical collections to specify which category attribute to use
 	/** array of dictionary term ids belonging to this collection */
 	termIds: string[]
 	/** array of branch term ids belonging to this collection,
@@ -1647,6 +1639,17 @@ type TermCollection = {
 	}[]
 }
 
+type NumericTermCollection = TermCollectionBase & {
+	type: 'numeric'
+}
+
+type CategoricalTermCollection = TermCollectionBase & {
+	type: 'categorical'
+	categoryKeys: string[]
+}
+
+type TermCollection = NumericTermCollection | CategoricalTermCollection
+
 type SampleType = {
 	name: string
 	plural_name: string