diff --git a/index.test-d.ts b/index.test-d.ts
index 016cf0c19..61848a2da 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -17,6 +17,17 @@ import tippy, {
   CreateSingletonInstance,
 } from './src/types';
 
+interface CustomProps {
+  custom: number;
+}
+
+type FilteredProps = CustomProps &
+  Omit<Props, keyof CustomProps | keyof LifecycleHooks>;
+
+type ExtendedProps = FilteredProps & LifecycleHooks<FilteredProps>;
+
+declare const tippyExtended: Tippy<ExtendedProps>;
+
 const singleTarget = document.createElement('div');
 const mulitpleTargets = document.querySelectorAll('div');
 
@@ -37,6 +48,8 @@ expectType<DelegateInstance[]>(
 );
 
 const tippyInstances = [tippy(singleTarget), tippy(singleTarget)];
+const singleton = createSingleton(tippyInstances);
+
 expectType<CreateSingletonInstance>(createSingleton(tippyInstances));
 expectType<CreateSingletonInstance>(
   createSingleton(tippyInstances, {content: 'hello'})
@@ -44,6 +57,12 @@ expectType<CreateSingletonInstance>(
 expectType<CreateSingletonInstance>(
   createSingleton(tippyInstances, {overrides: ['content']})
 );
+expectType<(instances: Instance<any>[]) => void>(singleton.setInstances);
+
+// TODO: I want to assert that these *don't* error, but `tsd` does not provide
+// such a function(?)
+createSingleton(tippyExtended('button'));
+singleton.setInstances(tippyExtended('button'));
 
 expectType<Instance>(
   tippy(singleTarget, {
@@ -51,17 +70,6 @@ expectType<Instance>(
   })
 );
 
-interface CustomProps {
-  custom: number;
-}
-
-type FilteredProps = CustomProps &
-  Omit<Props, keyof CustomProps | keyof LifecycleHooks>;
-
-type ExtendedProps = FilteredProps & LifecycleHooks<FilteredProps>;
-
-declare const tippyExtended: Tippy<ExtendedProps>;
-
 const customPlugin: Plugin<ExtendedProps> = {
   name: 'custom',
   defaultValue: 42,
diff --git a/src/types.ts b/src/types.ts
index 2e8845885..ab8c9e870 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -185,11 +185,11 @@ export type CreateSingletonProps<TProps = Props> = TProps & {
 export type CreateSingletonInstance<TProps = CreateSingletonProps> = Instance<
   TProps
 > & {
-  setInstances(instances: Instance<TProps>[]): void;
+  setInstances(instances: Instance<any>[]): void;
 };
 
 export type CreateSingleton<TProps = Props> = (
-  tippyInstances: Instance<TProps | Props>[],
+  tippyInstances: Instance<any>[],
   optionalProps?: Partial<CreateSingletonProps<TProps>>
 ) => CreateSingletonInstance<CreateSingletonProps<TProps>>;