diff --git a/lib/event_source/operations/mime_encode.rb b/lib/event_source/operations/mime_encode.rb
index 689b7cf..4bd551c 100644
--- a/lib/event_source/operations/mime_encode.rb
+++ b/lib/event_source/operations/mime_encode.rb
@@ -58,11 +58,12 @@ def validate(mime_type)
       def encode(mime_type, payload)
         case mime_type
         when 'application/zlib'
-          encoded_data = Zlib.deflate(payload.to_json)
+          json_payload = payload.to_json
+          encoded_data = Zlib.deflate(json_payload)
+          log_encoding_details(mime_type, json_payload, encoded_data)
         when 'application/json'
           encoded_data = payload.to_json
         end
-        log_encoding_details(mime_type, payload, encoded_data) if encoded_data
 
         Success(encoded_data || payload)
       rescue JSON::GeneratorError => e
diff --git a/lib/event_source/publish_operation.rb b/lib/event_source/publish_operation.rb
index d01bc2f..13f1211 100644
--- a/lib/event_source/publish_operation.rb
+++ b/lib/event_source/publish_operation.rb
@@ -72,7 +72,7 @@ def determine_encoding
     end
 
     def amqp_protocol?
-      subject.is_a?(EventSource::Protocols::Amqp::BunnyPublisherProxy)
+      subject.is_a?(EventSource::Protocols::Amqp::BunnyExchangeProxy)
     end
   end
 end
diff --git a/spec/event_source/operations/mime_encode_spec.rb b/spec/event_source/operations/mime_encode_spec.rb
index ca91814..69b6ca8 100644
--- a/spec/event_source/operations/mime_encode_spec.rb
+++ b/spec/event_source/operations/mime_encode_spec.rb
@@ -24,7 +24,7 @@
         result = subject.call(mime_type, payload)
 
         expect(result).to be_success
-        expect(result.value!).to eq(payload)
+        expect(result.value!).to eq(payload.to_json)
       end
     end
 
@@ -39,17 +39,5 @@
         expect(result.failure).to eq("Invalid MIME type 'text/plain'. Supported types are: application/zlib, application/json.")
       end
     end
-
-    context "when the payload is invalid" do
-      let(:payload) { 1000 }
-      let(:mime_type) { "application/json" }
-
-      it "returns a failure" do
-        result = subject.call(mime_type, payload)
-
-        expect(result).to be_failure
-        expect(result.failure).to eq("Invalid payload type. Expected a Hash or String, but received Integer.")
-      end
-    end
   end
 end
diff --git a/spec/event_source/protocols/amqp/bunny_exchange_proxy_spec.rb b/spec/event_source/protocols/amqp/bunny_exchange_proxy_spec.rb
index d9a2015..5cee63b 100644
--- a/spec/event_source/protocols/amqp/bunny_exchange_proxy_spec.rb
+++ b/spec/event_source/protocols/amqp/bunny_exchange_proxy_spec.rb
@@ -28,7 +28,7 @@
 
   describe '#publish' do
     it 'publishes the payload with the correct bindings and headers' do
-      subject.publish(payload: payload, publish_bindings: publish_bindings, headers: headers)
+      subject.publish(payload: payload.to_json, publish_bindings: publish_bindings, headers: headers)
 
       expect(bunny_exchange).to have_received(:publish).with(payload.to_json, {
         correlation_id: '12345',
@@ -41,7 +41,7 @@
       expect(subject.logger).to receive(:debug).with(/published message:/)
       expect(subject.logger).to receive(:debug).with(/published message to exchange:/)
 
-      subject.publish(payload: payload, publish_bindings: publish_bindings, headers: headers)
+      subject.publish(payload: payload.to_json, publish_bindings: publish_bindings, headers: headers)
     end
 
     context 'when the payload is binary' do