diff --git a/packages/react-reconciler/src/ReactFiberRoot.new.js b/packages/react-reconciler/src/ReactFiberRoot.new.js
index 892fe78ac1b1e..beaa5f509bc95 100644
--- a/packages/react-reconciler/src/ReactFiberRoot.new.js
+++ b/packages/react-reconciler/src/ReactFiberRoot.new.js
@@ -15,6 +15,7 @@ import type {
 } from './ReactInternalTypes';
 import type {RootTag} from './ReactRootTags';
 import type {Cache} from './ReactFiberCacheComponent.new';
+import type {Container} from './ReactFiberHostConfig';
 
 import {noTimeout, supportsHydration} from './ReactFiberHostConfig';
 import {createHostRootFiber} from './ReactFiber.new';
@@ -128,7 +129,7 @@ function FiberRootNode(
 }
 
 export function createFiberRoot(
-  containerInfo: any,
+  containerInfo: Container,
   tag: RootTag,
   hydrate: boolean,
   initialChildren: ReactNodeList,
diff --git a/packages/react-reconciler/src/ReactFiberRoot.old.js b/packages/react-reconciler/src/ReactFiberRoot.old.js
index f7e16f0bbdcc8..11221f86a8f4c 100644
--- a/packages/react-reconciler/src/ReactFiberRoot.old.js
+++ b/packages/react-reconciler/src/ReactFiberRoot.old.js
@@ -15,6 +15,7 @@ import type {
 } from './ReactInternalTypes';
 import type {RootTag} from './ReactRootTags';
 import type {Cache} from './ReactFiberCacheComponent.old';
+import type {Container} from './ReactFiberHostConfig';
 
 import {noTimeout, supportsHydration} from './ReactFiberHostConfig';
 import {createHostRootFiber} from './ReactFiber.old';
@@ -128,7 +129,7 @@ function FiberRootNode(
 }
 
 export function createFiberRoot(
-  containerInfo: any,
+  containerInfo: Container,
   tag: RootTag,
   hydrate: boolean,
   initialChildren: ReactNodeList,