--- a/src/Makefile	2020-05-21 18:54:31.176399032 +0200
+++ b/src/Makefile	2020-05-21 18:55:27.881498310 +0200
@@ -65,7 +65,7 @@
 %.cmx: %.ml
 	$(OCAMLOPT) $(CAMLOPTFLAGS) -c $*.ml
 %.$(O): %.c
-	$(OCAMLC) -ccopt -DBNG_ARCH_$(BNG_ARCH) -c $*.c
+	$(OCAMLC) -ccopt "-DBNG_ARCH_$(BNG_ARCH) $(CFLAGS)" -c $*.c
 
 # Legacy installation: files go into OCaml's stdlib directory; only META
 # is installed via findlib