diff --git a/pubspec.yaml b/pubspec.yaml
index c6da3a2f1..52eb8a43c 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -23,7 +23,7 @@ dependencies:
   package_config: ^2.0.0
   path: ^1.8.0
   pool: ^1.5.1
-  protobuf: ^2.0.0
+  protobuf: ">=2.0.0 <4.0.0"
   pub_semver: ^2.0.0
   source_maps: ^0.10.10
   source_span: ^1.10.0
@@ -46,7 +46,7 @@ dev_dependencies:
   grinder: ^0.9.0
   node_preamble: ^2.0.2
   lints: ^2.0.0
-  protoc_plugin: ^20.0.0
+  protoc_plugin: ">=20.0.0 <22.0.0"
   pub_api_client: ^2.1.1
   pubspec_parse: ^1.0.0
   test: ^1.16.7