diff --git a/reactos/dll/win32/avifil32/avifil32.rbuild b/reactos/dll/win32/avifil32/avifil32.rbuild
index 9e04b5204b1..854672b482c 100644
--- a/reactos/dll/win32/avifil32/avifil32.rbuild
+++ b/reactos/dll/win32/avifil32/avifil32.rbuild
@@ -6,6 +6,7 @@
 	<importlibrary definition="avifil32.spec.def" />
 	<include base="avifil32">.</include>
 	<include base="ReactOS">include/reactos/wine</include>
+	<define name="__WINESRC__" />
 	<define name="WINVER">0x600</define>
 	<define name="_WIN32_WINNT">0x600</define>
 	<file>acmstream.c</file>