diff --git a/cmd/protoc-gen-go-grpc/testdata/go.mod b/cmd/protoc-gen-go-grpc/testdata/go.mod
index 1f993b6a..c987bb92 100644
--- a/cmd/protoc-gen-go-grpc/testdata/go.mod
+++ b/cmd/protoc-gen-go-grpc/testdata/go.mod
@@ -3,7 +3,7 @@ module google.golang.org/protobuf/cmd/protoc-gen-go-grpc/testdata
 go 1.9
 
 require (
-	github.com/golang/protobuf v1.3.2
+	github.com/golang/protobuf v1.4.0-rc.1
 	google.golang.org/grpc v1.27.0-pre.0.20200124224931-7afcfdd66b12
 	google.golang.org/protobuf v1.0.0
 )
diff --git a/cmd/protoc-gen-go/testdata/go.mod b/cmd/protoc-gen-go/testdata/go.mod
index 7b4b263d..37f29344 100644
--- a/cmd/protoc-gen-go/testdata/go.mod
+++ b/cmd/protoc-gen-go/testdata/go.mod
@@ -3,7 +3,7 @@ module google.golang.org/protobuf/cmd/protoc-gen-go/testdata
 go 1.9
 
 require (
-	github.com/golang/protobuf v1.2.1-0.20191106221148-0fd87f0c3acd
+	github.com/golang/protobuf v1.4.0-rc.1
 	google.golang.org/protobuf v1.0.0
 )