diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2e814ea..8dbc57d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,14 +4,17 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Set up Go
-        uses: actions/setup-go@v4
+        uses: actions/setup-go@v5
         with:
           go-version: '1.20'
       - name: Install Protoc
         run: |
-          sudo apt install -y protobuf-compiler
+          curl -LO https://github.com/protocolbuffers/protobuf/releases/download/v28.1/protoc-28.1-linux-x86_64.zip
+          unzip protoc-28.1-linux-x86_64.zip -d $HOME/.local
+          export PATH="$PATH:$HOME/.local/bin"
+          protoc --version
           go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
       - name: Test
         run: make test
diff --git a/go.mod b/go.mod
index bcda4fc..4c3731f 100644
--- a/go.mod
+++ b/go.mod
@@ -4,7 +4,7 @@ go 1.19
 
 require (
 	github.com/stretchr/testify v1.8.1
-	google.golang.org/protobuf v1.28.1
+	google.golang.org/protobuf v1.34.2
 )
 
 require (
diff --git a/go.sum b/go.sum
index 1b2c304..75c0e0c 100644
--- a/go.sum
+++ b/go.sum
@@ -1,8 +1,6 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
-github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
@@ -14,10 +12,8 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
-google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
-google.golang.org/protobuf v1.28.1 h1:d0NfwRgPtno5B1Wa6L2DAG+KivqkdutMf1UhdNx175w=
-google.golang.org/protobuf v1.28.1/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/pkg/protodump/fixtures/test.proto3 b/pkg/protodump/fixtures/test.proto3
index 255a253..f00ed10 100644
--- a/pkg/protodump/fixtures/test.proto3
+++ b/pkg/protodump/fixtures/test.proto3
@@ -34,6 +34,7 @@ message HelloRequest {
   .hello.world.HelloRequest.Test blah = 2;
   .hello.world.HelloRequest.NestedEnum blahblah = 3;
   .hello.world.HelloReply blaha = 4;
+  optional string version = 5;
 }
 
 message HelloReply {
diff --git a/pkg/protodump/proto.go b/pkg/protodump/proto.go
index 7336680..d9261ad 100644
--- a/pkg/protodump/proto.go
+++ b/pkg/protodump/proto.go
@@ -108,16 +108,20 @@ func (pd *ProtoDefinition) writeType(field protoreflect.FieldDescriptor) {
 
 func (pd *ProtoDefinition) writeOneof(oneof protoreflect.OneofDescriptor) {
 	// TODO need to handle oneof options
-	pd.writeIndented("")
-	pd.write("oneof ")
-	pd.write(string(oneof.Name()))
-	pd.write(" {\n")
-	pd.indent()
-	for i := 0; i < oneof.Fields().Len(); i++ {
-		pd.writeField(oneof.Fields().Get(i))
+	if oneof.IsSynthetic() {
+		pd.writeField(oneof.Fields().Get(0))
+	} else {
+		pd.writeIndented("")
+		pd.write("oneof ")
+		pd.write(string(oneof.Name()))
+		pd.write(" {\n")
+		pd.indent()
+		for i := 0; i < oneof.Fields().Len(); i++ {
+			pd.writeField(oneof.Fields().Get(i))
+		}
+		pd.dedent()
+		pd.writeIndented("}\n")
 	}
-	pd.dedent()
-	pd.writeIndented("}\n")
 }
 
 func (pd *ProtoDefinition) writeField(field protoreflect.FieldDescriptor) {