diff --git a/make/topdir-autoconf.mk b/make/topdir-autoconf.mk
index a861484c..8f3e6894 100644
--- a/make/topdir-autoconf.mk
+++ b/make/topdir-autoconf.mk
@@ -1,9 +1,9 @@
-ifeq ($(wildcard $(TOPDIR)/make/defs.mk),)
-  ifneq ($(wildcard $(TOPDIR)/make/defs.mk.in),)
+AUTOCONF_IN            = $(wildcard *.in */*.in)
+AUTOCONF_GENERATED     = $(patsubst %.in,%,$(AUTOCONF_IN))
+
+ifneq ($(AUTOCONF_IN),)
+  ifneq ($(AUTOCONF_GENERATED),$(wildcard $(AUTCONF_GENERATED)))
     include $(MODDIR)/make/autoconf.mk
-  else
-    include $(MODDIR)/make/topdir.mk
   endif
-else
-  include $(MODDIR)/make/topdir.mk
 endif
+include $(MODDIR)/make/topdir.mk