diff --git a/packages/components/src/unit-control/types.ts b/packages/components/src/unit-control/types.ts
index ba55d63c44fa24..0cbebf4dd2ce03 100644
--- a/packages/components/src/unit-control/types.ts
+++ b/packages/components/src/unit-control/types.ts
@@ -1,7 +1,7 @@
 /**
  * External dependencies
  */
-import type { SyntheticEvent } from 'react';
+import type { CSSProperties, SyntheticEvent } from 'react';
 
 /**
  * Internal dependencies
@@ -79,6 +79,7 @@ export type UnitSelectControlProps = {
 
 export type UnitControlProps = UnitSelectControlProps & {
 	__unstableStateReducer?: StateReducer;
+	__unstableInputWidth?: CSSProperties[ 'width' ];
 	/**
 	 * If `true`, the unit `<select>` is hidden.
 	 *