diff --git a/lib/temporal/connection/converter/payload/proto_json.rb b/lib/temporal/connection/converter/payload/proto_json.rb
index 6d952a60..cdbc36f9 100644
--- a/lib/temporal/connection/converter/payload/proto_json.rb
+++ b/lib/temporal/connection/converter/payload/proto_json.rb
@@ -25,7 +25,7 @@ def to_payload(data)
                 'encoding' => ENCODING,
                 'messageType' => data.class.descriptor.name,
               },
-              data: data.to_json,
+              data: data.to_json.b,
             )
           end
         end
diff --git a/spec/unit/lib/temporal/connection/converter/payload/proto_json_spec.rb b/spec/unit/lib/temporal/connection/converter/payload/proto_json_spec.rb
index 21111d5f..589c921f 100644
--- a/spec/unit/lib/temporal/connection/converter/payload/proto_json_spec.rb
+++ b/spec/unit/lib/temporal/connection/converter/payload/proto_json_spec.rb
@@ -15,6 +15,13 @@
 
       expect(subject.from_payload(subject.to_payload(input))).to eq(input)
     end
+
+    it 'encodes special characters' do
+      input = Temporalio::Api::Common::V1::Payload.new(
+        metadata: { 'it’ll work!' => 'bytebytebyte' },
+      )
+      expect(subject.from_payload(subject.to_payload(input))).to eq(input)
+    end
   end
 
   it 'skips if not proto message' do