diff --git a/index.js.flow b/index.js.flow
index 872a156..622caaa 100644
--- a/index.js.flow
+++ b/index.js.flow
@@ -1,4 +1,4 @@
-// @flow
+// @flow strict
 
 type TemplateStringsArray = $ReadOnlyArray<string>;
 
diff --git a/package.json b/package.json
index 0893783..bc32468 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "chalk",
-	"version": "2.4.1",
+	"version": "2.4.2",
 	"description": "Terminal string styling done right",
 	"license": "MIT",
 	"repository": "chalk/chalk",