diff --git a/src/mod/codecs/mod_codec_g729/Makefile b/src/mod/codecs/mod_codec_g729/Makefile
index 745616eede..3b9afa36ac 100644
--- a/src/mod/codecs/mod_codec_g729/Makefile
+++ b/src/mod/codecs/mod_codec_g729/Makefile
@@ -1,3 +1,4 @@
+CFLAGS += -I$(PREFIX)/include/g729
 LDFLAGS +=-lg729
 
 all:	depends $(MODNAME).so