diff --git a/pubspec.yaml b/pubspec.yaml
index 75f82b1..b2e294a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -19,7 +19,7 @@ dependencies:
   meta: ^1.3.0
   http: '>=0.13.0 <2.0.0'
   http2: ^2.2.0
-  protobuf: '>=2.0.0 <4.0.0'
+  protobuf: ">=2.0.0 <5.0.0"
   clock: ^1.1.1
   web: ^1.1.0