diff --git a/libi2pd/Streaming.cpp b/libi2pd/Streaming.cpp
index c099e538..1974cd10 100644
--- a/libi2pd/Streaming.cpp
+++ b/libi2pd/Streaming.cpp
@@ -326,12 +326,16 @@ namespace stream
 			LogPrint (eLogInfo, "Streaming: Invalid option size ", optionSize, " Discarded");
 			return false;
 		}	
+		if (!flags) return true;
+		bool immediateAckRequested = false;
 		if (flags & PACKET_FLAG_DELAY_REQUESTED)
 		{
-			if (!m_IsAckSendScheduled)
+			uint16_t delayRequested = bufbe16toh (optionData);
+			if (!delayRequested) // 0 requests an immediate ack
+				immediateAckRequested = true;
+			else if (!m_IsAckSendScheduled)
 			{
-				uint16_t delayRequested = bufbe16toh (optionData);
-				if (delayRequested > 0 && delayRequested < m_RTT)
+				if (delayRequested < m_RTT)
 				{
 					m_IsAckSendScheduled = true;
 					m_AckSendTimer.expires_from_now (boost::posix_time::milliseconds(delayRequested));
@@ -432,6 +436,8 @@ namespace stream
 				return false;
 			}
 		}
+		if (immediateAckRequested)
+			SendQuickAck ();
 		return true;
 	}
 
diff --git a/libi2pd/Streaming.h b/libi2pd/Streaming.h
index c251d822..c0b73162 100644
--- a/libi2pd/Streaming.h
+++ b/libi2pd/Streaming.h
@@ -283,7 +283,7 @@ namespace stream
 			float m_WindowSize, m_LastWindowDropSize, m_WindowDropTargetSize;
 			int m_WindowIncCounter, m_RTO, m_AckDelay, m_PrevRTTSample;
 			double m_Jitter;
-			uint64_t m_MinPacingTime, m_PacingTime, m_PacingTimeRem, m_DropWindowDelayTime, m_LastSendTime; // microseconds
+			uint64_t m_MinPacingTime, m_PacingTime, m_PacingTimeRem, m_LastSendTime; // microseconds
 			uint64_t m_LastACKSendTime, m_PacketACKInterval, m_PacketACKIntervalRem; // for limit inbound speed
 			int m_NumResendAttempts, m_NumPacketsToSend;
 			size_t m_MTU;