diff --git a/dlls/amstream/tests/Makefile.in b/dlls/amstream/tests/Makefile.in
index 48b07d1b097..eb756ddf39d 100644
--- a/dlls/amstream/tests/Makefile.in
+++ b/dlls/amstream/tests/Makefile.in
@@ -1,6 +1,5 @@
 TESTDLL   = amstream.dll
 IMPORTS   = strmbase strmiids uuid ddraw ole32 user32
-EXTRADEFS = -DWINE_NO_NAMELESS_EXTENSION
 
 C_SRCS = \
 	amstream.c
diff --git a/dlls/amstream/tests/amstream.c b/dlls/amstream/tests/amstream.c
index f422a6a8db9..2c5252d8eed 100644
--- a/dlls/amstream/tests/amstream.c
+++ b/dlls/amstream/tests/amstream.c
@@ -20,6 +20,7 @@
 
 #define COBJMACROS
 #define NONAMELESSUNION
+#define WINE_NO_NAMELESS_EXTENSION
 
 #include "wine/test.h"
 #include "dshow.h"