diff --git a/docs/rules/filename-case.md b/docs/rules/filename-case.md
index e3da4b009c..010afa345c 100644
--- a/docs/rules/filename-case.md
+++ b/docs/rules/filename-case.md
@@ -50,7 +50,7 @@ You can set the `case` option like this:
 
 ### cases
 
-Type: `{[type: string]: string}`
+Type: `{[type: string]: boolean}`
 
 You can set the `cases` option to allow multiple cases: