diff --git a/src/video/directfb/Makefile.am b/src/video/directfb/Makefile.am
index c3e628c4297d260e7d1b7e11a8c9b5ed1bcf0fb0..ffa21ebdbc2a32e6e32d4a52b6bd81433d3ad091 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)