diff --git a/config/rules.mk b/config/rules.mk
index c6da046a0d3..62ad520336a 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -788,10 +788,17 @@ ifneq (,$(filter-out OS2 WINNT,$(OS_ARCH)))
 $(MKDEPENDENCIES)::
 	@$(MAKE_OBJDIR)
 	touch $(MKDEPENDENCIES)
+ifdef USE_AUTOCONF
+	$(MKDEPEND) -p$(OBJDIR_NAME)/ -o'.o' -f$(MKDEPENDENCIES) $(INCLUDES) $(a
+ddprefix $(srcdir)/,$(CSRCS) $(CPPSRCS))
+	@mv depend.mk depend.mk.old && cat depend.mk.old | sed "s|^$(OBJDIR_NAME
+)/$(srcdir)/|$(OBJDIR_NAME)/|g" > depend.mk && rm -f depend.mk.old
+else
 	$(MKDEPEND) -p$(OBJDIR_NAME)/ -o'.o' -f$(MKDEPENDENCIES) $(INCLUDES) $(CSRCS) $(CPPSRCS)
+endif
 
 $(MKDEPEND)::
-	cd $(DEPTH)/config; $(MAKE) nsinstall
+	cd $(DEPTH)/config; $(MAKE) nsinstall tweak_nspr
 	cd $(MKDEPEND_DIR); $(MAKE)
 
 # Rules to for detection