diff --git a/server/shadow/shadow_client.c b/server/shadow/shadow_client.c
index 34ff24535..414df5c7e 100644
--- a/server/shadow/shadow_client.c
+++ b/server/shadow/shadow_client.c
@@ -594,21 +594,19 @@ static BOOL shadow_client_surface_frame_acknowledge(rdpShadowClient* client,
         UINT32 frameId)
 {
 	shadow_client_common_frame_acknowledge(client, frameId);
+	/*
+	 * Reset queueDepth for legacy none RDPGFX acknowledge
+	 */
+	client->encoder->queueDepth = QUEUE_DEPTH_UNAVAILABLE;
 	return TRUE;
 }
 
 static UINT shadow_client_rdpgfx_frame_acknowledge(RdpgfxServerContext* context,
         RDPGFX_FRAME_ACKNOWLEDGE_PDU* frameAcknowledge)
 {
-	shadow_client_common_frame_acknowledge((rdpShadowClient*)context->custom,
-	                                       frameAcknowledge->frameId);
-	return CHANNEL_RC_OK;
-}
-static UINT shadow_client_rdpgfx_qoe_frame_acknowledge(RdpgfxServerContext*
-        context, RDPGFX_QOE_FRAME_ACKNOWLEDGE_PDU* qoeFrameAcknowledge)
-{
-	shadow_client_common_frame_acknowledge((rdpShadowClient*)context->custom,
-	                                       qoeFrameAcknowledge->frameId);
+	rdpShadowClient* client = (rdpShadowClient*)context->custom;
+	shadow_client_common_frame_acknowledge(client, frameAcknowledge->frameId);
+	client->encoder->queueDepth = frameAcknowledge->queueDepth;
 	return CHANNEL_RC_OK;
 }
 
@@ -1602,8 +1600,6 @@ static void* shadow_client_thread(rdpShadowClient* client)
 					    !gfxstatus.gfxOpened)
 					{
 						client->rdpgfx->FrameAcknowledge = shadow_client_rdpgfx_frame_acknowledge;
-						client->rdpgfx->QoeFrameAcknowledge =
-						    shadow_client_rdpgfx_qoe_frame_acknowledge;
 						client->rdpgfx->CapsAdvertise = shadow_client_rdpgfx_caps_advertise;
 
 						if (!client->rdpgfx->Open(client->rdpgfx))
diff --git a/server/shadow/shadow_encoder.c b/server/shadow/shadow_encoder.c
index 8fc77ef27..b9d1cb55b 100644
--- a/server/shadow/shadow_encoder.c
+++ b/server/shadow/shadow_encoder.c
@@ -34,12 +34,15 @@ int shadow_encoder_preferred_fps(rdpShadowEncoder* encoder)
 
 UINT32 shadow_encoder_inflight_frames(rdpShadowEncoder* encoder)
 {
-	/* Return inflight frame count =
+	/* Return inflight frame count.
+	 * If queueDepth is SUSPEND_FRAME_ACKNOWLEDGEMENT, count = 0
+	 * Otherwise, calculate count =
 	 * <last sent frame id> - <last client-acknowledged frame id>
 	 * Note: This function is exported so that subsystem could
 	 * implement its own strategy to tune fps.
 	 */
-	return encoder->frameId - encoder->lastAckframeId;
+	return (encoder->queueDepth == SUSPEND_FRAME_ACKNOWLEDGEMENT) ? 0 : encoder->frameId -
+	       encoder->lastAckframeId;
 }
 
 UINT32 shadow_encoder_create_frame_id(rdpShadowEncoder* encoder)
diff --git a/server/shadow/shadow_encoder.h b/server/shadow/shadow_encoder.h
index b2c01b908..611850d1d 100644
--- a/server/shadow/shadow_encoder.h
+++ b/server/shadow/shadow_encoder.h
@@ -56,6 +56,7 @@ struct rdp_shadow_encoder
 	BOOL frameAck;
 	UINT32 frameId;
 	UINT32 lastAckframeId;
+	UINT32 queueDepth;
 };
 
 #ifdef __cplusplus