--- alt-ergo-1.30.old/Makefile.users	2017-11-09 09:55:47.337871409 +0000
+++ alt-ergo-1.30/Makefile.users	2017-11-09 10:00:52.374639872 +0000
@@ -140,14 +140,14 @@
 	$(OCAMLC) $(BFLAGS) -o $@ $(BIBBYTE) $^
 
 $(NAME).opt: $(MAINCMX)
-	$(OCAMLOPT) $(OFLAGS) -o $@ $(BIBOPT) $^
+	$(OCAMLOPT) $(OFLAGS) -runtime-variant _pic -o $@ $(BIBOPT) $^
 
 ####
 $(GUINAME).byte: $(GUICMO)
 	$(OCAMLC) $(BFLAGS) -o $(GUINAME).byte $(BIBBYTE) $(BIBGUIBYTE) $^
 
 $(GUINAME).opt: $(GUICMX)
-	$(OCAMLOPT) $(OFLAGS) -o $(GUINAME).opt $(BIBOPT) $(BIBGUIOPT) $^
+	$(OCAMLOPT) $(OFLAGS) -runtime-variant _pic -o $(GUINAME).opt $(BIBOPT) $(BIBGUIOPT) $^
 
 ifeq ($(ENABLEGUI),yes)
 gui: $(GUINAME).$(OCAMLBEST)