diff --git a/src/Bus.cc b/src/Bus.cc
index 8737fa45..96684305 100644
--- a/src/Bus.cc
+++ b/src/Bus.cc
@@ -486,7 +486,7 @@ namespace kickcat
 
             auto process = [pi_frame](DatagramHeader const*, uint8_t const* data, uint16_t wkc)
             {
-                if (wkc != pi_frame.inputs.size())
+                if (wkc != (pi_frame.inputs.size() + pi_frame.outputs.size() * 2))
                 {
                     DEBUG_PRINT("Invalid working counter\n");
                     return DatagramState::INVALID_WKC;
diff --git a/unit/bus-t.cc b/unit/bus-t.cc
index bb70f826..33fe83fe 100644
--- a/unit/bus-t.cc
+++ b/unit/bus-t.cc
@@ -322,7 +322,7 @@ TEST_F(BusTest, logical_cmd)
     logical_write = 0x1716151413121110;
     std::memcpy(slave.output.data, &logical_write, sizeof(int64_t));
     checkSendFrame(Command::LRW, logical_write);
-    handleReply<int64_t>({logical_read});
+    handleReply<int64_t>({logical_read}, 3);
     bus.processDataReadWrite([](DatagramState const&){});
 
     for (int i = 0; i < 8; ++i)