diff --git a/r2/r2/controllers/api.py b/r2/r2/controllers/api.py
index f0d8f5bba..f75142157 100755
--- a/r2/r2/controllers/api.py
+++ b/r2/r2/controllers/api.py
@@ -2785,7 +2785,7 @@ class ApiController(RedditController):
         c.user._commit()
         form.redirect("/prefs/otp")
 
-    @json_validate(query=VPrintable("query", max_length=50))
+    @json_validate(query=VLength("query", max_length=50))
     @api_doc(api_section.subreddits, extensions=["json"])
     def GET_subreddits_by_topic(self, responder, query):
         if not g.CLOUDSEARCH_SEARCH_API: