diff --git a/core/src/utils/animation/animation-interface.ts b/core/src/utils/animation/animation-interface.ts
index 00c50d5099..6c58d3681c 100644
--- a/core/src/utils/animation/animation-interface.ts
+++ b/core/src/utils/animation/animation-interface.ts
@@ -29,9 +29,9 @@ export interface Animation {
    */
   destroy(clearStyleSheets?: boolean): void;
 
-  progressStart(forceLinearEasing: boolean, step?: number): void;
-  progressStep(step: number): void;
-  progressEnd(playTo: 0 | 1 | undefined, step: number, dur?: number): void;
+  progressStart(forceLinearEasing?: boolean, step?: number): Animation;
+  progressStep(step: number): Animation;
+  progressEnd(playTo: 0 | 1 | undefined, step: number, dur?: number): Animation;
 
   from(property: string, value: any): Animation;
   to(property: string, value: any): Animation;