diff --git a/packages/slate-dev-environment/src/index.js b/packages/slate-dev-environment/src/index.js
index b6c822d45..b0eb3596c 100644
--- a/packages/slate-dev-environment/src/index.js
+++ b/packages/slate-dev-environment/src/index.js
@@ -111,3 +111,6 @@ export const IS_WINDOWS = os === 'windows'
 
 export const HAS_INPUT_EVENTS_LEVEL_1 = features.includes('inputeventslevel1')
 export const HAS_INPUT_EVENTS_LEVEL_2 = features.includes('inputeventslevel2')
+
+// COMPAT: this is needed for an older version of `slate-react` support.
+export const SUPPORTED_EVENTS = { beforeinput: HAS_INPUT_EVENTS_LEVEL_2 }