diff --git a/res/Makefile b/res/Makefile
index ea533f932d29a1191084dafeda63f5c5e5b31f76..686ca9718ddfe7478d9507aef7129fd37c2429bd 100755
--- a/res/Makefile
+++ b/res/Makefile
@@ -16,7 +16,7 @@ MODS=res_adsi.so res_parking.so res_crypto.so res_musiconhold.so res_indications
 CRYPTO_LIBS=-lssl -lcrypto
 
 CFLAGS+=
-CFLAGS+=$(shell [ -f /usr/include/zap.h ] && echo " -DZAPATA_MOH")
+CFLAGS+=$(shell [ -f /usr/include/linux/zaptel.h ] && echo " -DZAPATA_MOH")
 
 all: $(MODS)