diff --git a/gfx/thebes/src/Makefile.in b/gfx/thebes/src/Makefile.in
index 2d5efe828d28..a0013e332660 100644
--- a/gfx/thebes/src/Makefile.in
+++ b/gfx/thebes/src/Makefile.in
@@ -35,9 +35,11 @@ CPPSRCS	= \
 	gfxUserFontSet.cpp \
 	$(NULL)
 
+ifeq ($(MOZ_WIDGET_TOOLKIT),qt)
 CPPSRCS += \
 	gfxSharedImageSurface.cpp \
 	$(NULL)
+endif
 
 EXTRA_DSO_LDOPTS += \
 	$(MOZ_CAIRO_LIBS) \