diff --git a/lib/babel-packages.js.flow b/lib/babel-packages.js.flow
index 479e0f883c39..c2f9b713ea66 100644
--- a/lib/babel-packages.js.flow
+++ b/lib/babel-packages.js.flow
@@ -164,3 +164,7 @@ declare module "@babel/helper-function-name" {
     localBinding?: boolean
   ): any;
 }
+
+declare module "@babel/helper-split-export-declaration" {
+  declare export default function splitExportDeclaration(exportDeclaration: any): any;
+}
diff --git a/packages/babel-helper-split-export-declaration/src/index.js b/packages/babel-helper-split-export-declaration/src/index.ts
similarity index 100%
rename from packages/babel-helper-split-export-declaration/src/index.js
rename to packages/babel-helper-split-export-declaration/src/index.ts