diff --git a/libs/freetdm/mod_openzap/Makefile b/libs/freetdm/mod_openzap/Makefile
index fcee33c9d8..aa763e48d8 100644
--- a/libs/freetdm/mod_openzap/Makefile
+++ b/libs/freetdm/mod_openzap/Makefile
@@ -9,6 +9,6 @@ include $(BASE)/build/modmake.rules
 local_depend: $(OZA)
 
 $(OZA): 
-	cd $(OZ_DIR) && $(MAKE) ZAP_MODS="wanpipe zt" ZAP_CFLAGS="-g -ggdb"
+	cd $(OZ_DIR) && $(MAKE) ZAP_MODS="wanpipe zt" ZAP_CFLAGS="-g -ggdb $(ALL_CXXFLAGS)"