diff --git a/mediapipe/objc/MPPGraph.mm b/mediapipe/objc/MPPGraph.mm
index 3123eb863..275849f4a 100644
--- a/mediapipe/objc/MPPGraph.mm
+++ b/mediapipe/objc/MPPGraph.mm
@@ -107,6 +107,7 @@ void CallFrameDelegate(void* wrapperVoid, const std::string& streamName,
   MPPGraph* wrapper = (__bridge MPPGraph*)wrapperVoid;
   @autoreleasepool {
     if (packetType == MPPPacketTypeRaw) {
+      wrapper->_framesInFlight--;
       [wrapper.delegate mediapipeGraph:wrapper
                      didOutputPacket:packet
                           fromStream:streamName];