diff --git a/servant-event-stream.cabal b/servant-event-stream.cabal
index e2968bc..a653b40 100644
--- a/servant-event-stream.cabal
+++ b/servant-event-stream.cabal
@@ -31,7 +31,7 @@ library
     OverloadedStrings
 
   build-depends:
-    base >=4.10 && <4.20,
+    base >=4.10 && <4.22,
     bytestring >=0.11.1.0 && <0.13,
     http-media >=0.7.1.3 && <0.9,
     lens >=4.17 && <5.4,