diff -ru old/OMakefile new/OMakefile
--- old/OMakefile
+++ new/OMakefile
@@ -57,7 +57,7 @@
 #
 # OCaml options
 #
-OCAMLFLAGS[] += -w Ae$(if $(OCAML_ACCEPTS_Z_WARNING), z)
+OCAMLFLAGS[] += -w a
 if $(THREADS_ENABLED)
     OCAMLFLAGS += -thread
     export
