diff --git a/packages/babel-plugin-syntax-flow/src/index.js b/packages/babel-plugin-syntax-flow/src/index.js
index a7fcf7203a..7f80f4843a 100644
--- a/packages/babel-plugin-syntax-flow/src/index.js
+++ b/packages/babel-plugin-syntax-flow/src/index.js
@@ -7,6 +7,10 @@ export default declare((api, options) => {
   // the @flow pragma was provided.
   const { all } = options;
 
+  if (typeof all !== "boolean" && typeof all !== "undefined") {
+    throw new Error(".all must be a boolean, or undefined");
+  }
+
   return {
     manipulateOptions(opts, parserOpts) {
       // If the file has already enabled TS, assume that this is not a
diff --git a/packages/babel-preset-flow/src/index.js b/packages/babel-preset-flow/src/index.js
index 7dc163bdbf..6fbd56a196 100644
--- a/packages/babel-preset-flow/src/index.js
+++ b/packages/babel-preset-flow/src/index.js
@@ -1,10 +1,10 @@
 import { declare } from "@babel/helper-plugin-utils";
 import transformFlowStripTypes from "@babel/plugin-transform-flow-strip-types";
 
-export default declare(api => {
+export default declare((api, { all }) => {
   api.assertVersion(7);
 
   return {
-    plugins: [transformFlowStripTypes],
+    plugins: [[transformFlowStripTypes, { all }]],
   };
 });