diff --git a/config/flow/css.js.flow b/config/flow/css.js.flow
new file mode 100644
index 00000000000..46e7f7c0456
--- /dev/null
+++ b/config/flow/css.js.flow
@@ -0,0 +1 @@
+// @flow
diff --git a/config/flow/file.js.flow b/config/flow/file.js.flow
new file mode 100644
index 00000000000..701b6700f23
--- /dev/null
+++ b/config/flow/file.js.flow
@@ -0,0 +1,2 @@
+// @flow
+declare export default string;