diff --git a/dlls/traffic/traffic.spec b/dlls/traffic/traffic.spec
index 4638af31b01..ad4bce09dad 100644
--- a/dlls/traffic/traffic.spec
+++ b/dlls/traffic/traffic.spec
@@ -4,7 +4,7 @@
 @ stub TcCloseInterface
 @ stub TcDeleteFilter
 @ stub TcDeleteFlow
-@ stub TcDeregisterClient
+@ stdcall TcDeregisterClient(ptr)
 @ stub TcEnumerateFlows
 @ stub TcEnumerateInterfaces
 @ stub TcGetFlowNameA
diff --git a/dlls/traffic/traffic_main.c b/dlls/traffic/traffic_main.c
index 6efea899dda..6b8a9751e19 100644
--- a/dlls/traffic/traffic_main.c
+++ b/dlls/traffic/traffic_main.c
@@ -54,3 +54,12 @@ ULONG WINAPI TcRegisterClient(ULONG version, HANDLE context,
     if(buffer) *buffer = INVALID_HANDLE_VALUE;
     return ERROR_CALL_NOT_IMPLEMENTED;
 }
+
+/*****************************************************************************
+ * TcDeregisterClient [TRAFFIC.@]
+ */
+ULONG WINAPI TcDeregisterClient(HANDLE ClientHandle)
+{
+    FIXME("%p: stub\n", ClientHandle);
+    return ERROR_CALL_NOT_IMPLEMENTED;
+}