diff --git a/src/utils/map-state.d.ts b/src/utils/map-state.d.ts
index 6931789e..ad59358f 100644
--- a/src/utils/map-state.d.ts
+++ b/src/utils/map-state.d.ts
@@ -15,7 +15,7 @@ export type ViewportProps = Partial<{
   minZoom: number,
   maxPitch: number,
   minPitch: number,
-  transitionDuration: number,
+  transitionDuration: number | 'auto',
   transitionEasing: (t: number) => number,
   transitionInterpolator: TransitionInterpolator,
   transitionInterruption: number