diff --git a/src/video/directfb/Makefile.am b/src/video/directfb/Makefile.am
index c3e628c42..ffa21ebdb 100644
--- a/src/video/directfb/Makefile.am
+++ b/src/video/directfb/Makefile.am
@@ -1,7 +1,7 @@
 
 ## Makefile.am for SDL using the DirectFB video driver
 
-INCLUDES += $(DIRECTFB_CFLAGS)
+INCLUDES = $(DIRECTFB_CFLAGS)
 
 noinst_LTLIBRARIES = libvideo_directfb.la
 libvideo_directfb_la_SOURCES = $(DIRECTFB_SRCS)