diff --git a/src/sctptransport.cpp b/src/sctptransport.cpp
index 6ac988f..73b2aa1 100644
--- a/src/sctptransport.cpp
+++ b/src/sctptransport.cpp
@@ -533,13 +533,16 @@ void SctpTransport::updateBufferedAmount(uint16_t streamId, long delta) {
 	else
 		it->second = amount;
 
-	mSendMutex.unlock();
+	// Synchronously call the buffered amount callback
+	triggerBufferedAmount(streamId, amount);
+}
+
+void SctpTransport::triggerBufferedAmount(uint16_t streamId, size_t amount) {
 	try {
 		mBufferedAmountCallback(streamId, amount);
 	} catch (const std::exception &e) {
-		PLOG_DEBUG << "SCTP buffered amount callback: " << e.what();
+		PLOG_WARNING << "SCTP buffered amount callback: " << e.what();
 	}
-	mSendMutex.lock();
 }
 
 void SctpTransport::sendReset(uint16_t streamId) {
diff --git a/src/sctptransport.hpp b/src/sctptransport.hpp
index 2bae169..a9a78a1 100644
--- a/src/sctptransport.hpp
+++ b/src/sctptransport.hpp
@@ -83,6 +83,7 @@ private:
 	bool trySendQueue();
 	bool trySendMessage(message_ptr message);
 	void updateBufferedAmount(uint16_t streamId, long delta);
+	void triggerBufferedAmount(uint16_t streamId, size_t amount);
 	void sendReset(uint16_t streamId);
 	bool safeFlush();
 
@@ -97,7 +98,8 @@ private:
 
 	Processor mProcessor;
 	std::atomic<int> mPendingRecvCount;
-	std::mutex mRecvMutex, mSendMutex;
+	std::mutex mRecvMutex;
+	std::recursive_mutex mSendMutex; // buffered amount callback is synchronous
 	Queue<message_ptr> mSendQueue;
 	std::map<uint16_t, size_t> mBufferedAmount;
 	amount_callback mBufferedAmountCallback;