diff --git a/reactos/drivers/wdm/audio/backpln/portcls/dll.cpp b/reactos/drivers/wdm/audio/backpln/portcls/dll.cpp
index cd658a5c6e2..16a09dbf1c9 100644
--- a/reactos/drivers/wdm/audio/backpln/portcls/dll.cpp
+++ b/reactos/drivers/wdm/audio/backpln/portcls/dll.cpp
@@ -9,6 +9,8 @@
 
 #include "private.hpp"
 
+extern
+"C"
 ULONG
 NTAPI
 DllInitialize(ULONG Unknown)