diff --git a/packages/babel-core/src/config/validation/options.js b/packages/babel-core/src/config/validation/options.js
index 3edcd4d90bfa..c3e7f359cd90 100644
--- a/packages/babel-core/src/config/validation/options.js
+++ b/packages/babel-core/src/config/validation/options.js
@@ -376,6 +376,7 @@ function throwUnknownError(loc: OptionPath) {
         loc,
       )}. Check out https://babeljs.io/docs/en/babel-core/#options for more information about options.`,
     );
+    // $FlowIgnore
     unknownOptErr.code = "BABEL_UNKNOWN_OPTION";
 
     throw unknownOptErr;
diff --git a/packages/babel-core/src/config/validation/plugins.js b/packages/babel-core/src/config/validation/plugins.js
index 1990cb82dd83..06778caff269 100644
--- a/packages/babel-core/src/config/validation/plugins.js
+++ b/packages/babel-core/src/config/validation/plugins.js
@@ -101,6 +101,7 @@ export function validatePluginObject(obj: {}): PluginObject {
       const invalidPluginPropertyError = new Error(
         `.${key} is not a valid Plugin property`,
       );
+      // $FlowIgnore
       invalidPluginPropertyError.code = "BABEL_UNKNOWN_PLUGIN_PROPERTY";
       throw invalidPluginPropertyError;
     }