diff --git a/packages/react-params/src/Param/Vector.tsx b/packages/react-params/src/Param/Vector.tsx
index 966cd0c205..a66f348073 100644
--- a/packages/react-params/src/Param/Vector.tsx
+++ b/packages/react-params/src/Param/Vector.tsx
@@ -22,7 +22,8 @@ function getParam ([{ name, type }]: ParamDef[], index: number): ParamDef {
 }
 
 export function getParams (inputParams: ParamDef[], prev: ParamDef[], max: number): ParamDef[] {
-  if (prev.length === max) {
+  // HACK: I don't know why `max` changes to `undefined`.
+  if (prev.length === max || isUndefined(max)) {
     return prev;
   }
 
@@ -36,6 +37,10 @@ export function getParams (inputParams: ParamDef[], prev: ParamDef[], max: numbe
 }
 
 export function getValues ({ value }: RawParam): RawParam[] {
+  if (value instanceof Set) {
+    value = [...value.values()];
+  }
+
   return Array.isArray(value)
     ? value.map((value: RawParam) =>
       isUndefined(value) || isUndefined(value.isValid)
diff --git a/packages/react-params/src/Param/findComponent.ts b/packages/react-params/src/Param/findComponent.ts
index fd4e774459..dedd8c929b 100644
--- a/packages/react-params/src/Param/findComponent.ts
+++ b/packages/react-params/src/Param/findComponent.ts
@@ -74,7 +74,7 @@ const componentDef: TypeToComponent[] = [
   { c: Text, t: ['String', 'Text'] },
   { c: Struct, t: ['Struct'] },
   { c: Tuple, t: ['Tuple'] },
-  { c: Vector, t: ['Vec'] },
+  { c: Vector, t: ['Vec', 'BTreeSet'] },
   { c: VectorFixed, t: ['VecFixed'] },
   { c: Vote, t: ['Vote'] },
   { c: VoteThreshold, t: ['VoteThreshold'] },
@@ -121,6 +121,9 @@ function fromDef ({ displayName, info, lookupName, sub, type }: TypeDef): string
     case TypeDefInfo.Struct:
       return 'Struct';
 
+    case TypeDefInfo.BTreeSet:
+      return 'BTreeSet';
+
     case TypeDefInfo.Tuple:
       return components[type] === Account
         ? type