diff --git a/types/controllers/index.d.ts b/types/controllers/index.d.ts
index 2a659e636..8b8890633 100644
--- a/types/controllers/index.d.ts
+++ b/types/controllers/index.d.ts
@@ -237,7 +237,7 @@ export interface DoughnutController extends DatasetController {
   readonly offsetX: number;
   readonly offsetY: number;
 
-  getRingIndex(datasetIndex): number;
+  getRingIndex(datasetIndex: number): number;
   calculateTotal(): number;
   calculateCircumference(value: number): number;
 }
diff --git a/types/core/index.d.ts b/types/core/index.d.ts
index 10d48cc1b..1a487965d 100644
--- a/types/core/index.d.ts
+++ b/types/core/index.d.ts
@@ -356,7 +356,7 @@ export class DatasetController<E extends Element = Element, DSE extends Element
    * @protected
    */
 
-  protected updateElement(element, index, properties, mode: UpdateMode): void;
+  protected updateElement(element: E | DSE, index: number | undefined, properties: any, mode: UpdateMode): void;
   /**
    * Utility to animate the shared options, that are potentially affecting multiple elements.
    * @protected
diff --git a/types/helpers/helpers.interpolation.d.ts b/types/helpers/helpers.interpolation.d.ts
index e69de29bb..cb0ff5c3b 100644
--- a/types/helpers/helpers.interpolation.d.ts
+++ b/types/helpers/helpers.interpolation.d.ts
@@ -0,0 +1 @@
+export {};
diff --git a/types/helpers/helpers.math.d.ts b/types/helpers/helpers.math.d.ts
index ebe9d028b..784f00735 100644
--- a/types/helpers/helpers.math.d.ts
+++ b/types/helpers/helpers.math.d.ts
@@ -11,6 +11,6 @@ export function toDegrees(radians: number): number;
 export function getAngleFromPoint(
   centrePoint: { x: number; y: number },
   anglePoint: { x: number; y: number }
-): { angle; number; distance: number };
+): { angle: number; distance: number };
 
 export function distanceBetweenPoints(pt1: { x: number; y: number }, pt2: { x: number; y: number }): number;
diff --git a/types/helpers/helpers.segment.d.ts b/types/helpers/helpers.segment.d.ts
index e69de29bb..cb0ff5c3b 100644
--- a/types/helpers/helpers.segment.d.ts
+++ b/types/helpers/helpers.segment.d.ts
@@ -0,0 +1 @@
+export {};