--- a/gfx/ycbcr/Makefile.in
+++ b/gfx/ycbcr/Makefile.in
@@ -16,17 +16,17 @@ EXPORTS      = chromium_types.h \
                yuv_convert.h \
                yuv_row.h \
                $(NULL)
 
 CPPSRCS = yuv_convert.cpp \
           yuv_row_c.cpp \
           $(NULL)
 
-ifeq ($(MOZ_WIDGET_TOOLKIT),windows)
+ifdef _MSC_VER
 CPPSRCS += yuv_row_win.cpp \
            $(NULL)
 else
 ifeq ($(MOZ_WIDGET_TOOLKIT),gtk2)
 CPPSRCS += yuv_row_linux.cpp \
            $(NULL)
 else
 ifeq ($(MOZ_WIDGET_TOOLKIT),cocoa)