diff --git a/lib/ConsumerImpl.cc b/lib/ConsumerImpl.cc
index 52f04401..7a363bc1 100644
--- a/lib/ConsumerImpl.cc
+++ b/lib/ConsumerImpl.cc
@@ -84,6 +84,7 @@ ConsumerImpl::ConsumerImpl(const ClientImplPtr client, const std::string& topic,
       receiverQueueRefillThreshold_(config_.getReceiverQueueSize() / 2),
       consumerId_(client->newConsumerId()),
       consumerName_(config_.getConsumerName()),
+      consumerStr_("[" + topic + ", " + subscriptionName + ", " + std::to_string(consumerId_) + "] "),
       messageListenerRunning_(true),
       negativeAcksTracker_(client, *this, conf),
       readCompacted_(conf.isReadCompacted()),
@@ -92,10 +93,6 @@ ConsumerImpl::ConsumerImpl(const ClientImplPtr client, const std::string& topic,
       autoAckOldestChunkedMessageOnQueueFull_(conf.isAutoAckOldestChunkedMessageOnQueueFull()),
       expireTimeOfIncompleteChunkedMessageMs_(conf.getExpireTimeOfIncompleteChunkedMessageMs()),
       interceptors_(interceptors) {
-    std::stringstream consumerStrStream;
-    consumerStrStream << "[" << topic_ << ", " << subscription_ << ", " << consumerId_ << "] ";
-    consumerStr_ = consumerStrStream.str();
-
     // Initialize un-ACKed messages OT tracker.
     if (conf.getUnAckedMessagesTimeoutMs() != 0) {
         if (conf.getTickDurationInMs() > 0) {
diff --git a/lib/ConsumerImpl.h b/lib/ConsumerImpl.h
index 690d8fc4..7ca39799 100644
--- a/lib/ConsumerImpl.h
+++ b/lib/ConsumerImpl.h
@@ -215,7 +215,7 @@ class ConsumerImpl : public ConsumerImplBase {
     const int receiverQueueRefillThreshold_;
     uint64_t consumerId_;
     std::string consumerName_;
-    std::string consumerStr_;
+    const std::string consumerStr_;
     int32_t partitionIndex_ = -1;
     Promise<Result, ConsumerImplBaseWeakPtr> consumerCreatedPromise_;
     std::atomic_bool messageListenerRunning_;
diff --git a/lib/MessageCrypto.cc b/lib/MessageCrypto.cc
index bab96d1e..920e3fde 100644
--- a/lib/MessageCrypto.cc
+++ b/lib/MessageCrypto.cc
@@ -28,7 +28,7 @@ namespace pulsar {
 
 DECLARE_LOG_OBJECT()
 
-MessageCrypto::MessageCrypto(std::string& logCtx, bool keyGenNeeded)
+MessageCrypto::MessageCrypto(const std::string& logCtx, bool keyGenNeeded)
     : dataKeyLen_(32),
       dataKey_(new unsigned char[dataKeyLen_]),
       tagLen_(16),
diff --git a/lib/MessageCrypto.h b/lib/MessageCrypto.h
index fd139c1e..90b891e2 100644
--- a/lib/MessageCrypto.h
+++ b/lib/MessageCrypto.h
@@ -49,7 +49,7 @@ class MessageCrypto {
     typedef std::map<std::string, std::string> StringMap;
     typedef std::map<std::string, std::pair<std::string, boost::posix_time::ptime>> DataKeyCacheMap;
 
-    MessageCrypto(std::string& logCtx, bool keyGenNeeded);
+    MessageCrypto(const std::string& logCtx, bool keyGenNeeded);
     ~MessageCrypto();
 
     /*