diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index b24c67fc07..63b696708d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -240,6 +240,7 @@ EXTRALIBS += -L../libavutil -lavutil$(BUILDSUF)
 # currently using libdts for dts decoding
 ifeq ($(CONFIG_DTS),yes)
 OBJS+= dtsdec.o
+CFLAGS+= $(DTS_INC)
 endif
 
 ifeq ($(CONFIG_FAAD),yes)