diff --git a/packages/babel-plugin-extract-messages/src/index.js b/packages/babel-plugin-extract-messages/src/index.js
index a90370cb0..c2b7da473 100644
--- a/packages/babel-plugin-extract-messages/src/index.js
+++ b/packages/babel-plugin-extract-messages/src/index.js
@@ -213,26 +213,30 @@ export default function({ types: t }) {
        */
       const localeDir = this.opts.localeDir || opts.localeDir
       const { filename } = file.opts
+      const [basename] = fsPath.basename(filename).split(".", 2)
       const baseDir = fsPath.dirname(fsPath.relative(optsBaseDir, filename))
       const targetDir = fsPath.join(localeDir, "_build", baseDir)
 
       const messages = file.get(MESSAGES)
       const catalog = {}
+      const catalogFilename = fsPath.join(targetDir, `${basename}.json`)
 
       // no messages, skip file
-      if (!messages.size) return
+      if (!messages.size) {
+        // clean any existing catalog
+        if (fs.existsSync(catalogFilename)) {
+          fs.writeFileSync(catalogFilename, JSON.stringify({}))
+        }
+
+        return
+      }
 
       messages.forEach((value, key) => {
         catalog[key] = value
       })
 
       mkdirp.sync(targetDir)
-      const [basename] = fsPath.basename(filename).split(".", 2)
-
-      fs.writeFileSync(
-        fsPath.join(targetDir, `${basename}.json`),
-        JSON.stringify(catalog, null, 2)
-      )
+      fs.writeFileSync(catalogFilename, JSON.stringify(catalog, null, 2))
     }
   }
 }
diff --git a/packages/cli/src/api/formats/utils/locales.js b/packages/cli/src/api/formats/utils/locales.js
index 48905ebbf..43cf9ce7e 100644
--- a/packages/cli/src/api/formats/utils/locales.js
+++ b/packages/cli/src/api/formats/utils/locales.js
@@ -13,12 +13,12 @@ export type LocaleObject = {
  * 4. country code
  * @type {RegExp}
  */
-export const localeRe = new RegExp(/(([a-z]+)([_-]([a-zA-Z]+))?)(\\|\/)?/)
+export const localeRe = new RegExp(/(([a-z]+)([_-]([a-zA-Z]+))?)[\\/]?/)
 
 export function isValid(locale: string): boolean {
   const match = localeRe.exec(locale)
   return (
-    match &&
+    match !== null &&
     match[0] === locale && // locale has valid format
     match[2] in plurals // language is valid (we have plurals for it)
   )