diff --git a/src/cowboy_req.erl b/src/cowboy_req.erl
index fc82308f..09e1ee5e 100644
--- a/src/cowboy_req.erl
+++ b/src/cowboy_req.erl
@@ -88,7 +88,7 @@
 -export_type([cookie_opts/0]).
 
 -type read_body_opts() :: #{
-	length => non_neg_integer(),
+	length => non_neg_integer() | infinity,
 	period => non_neg_integer(),
 	timeout => timeout()
 }.