--- a/make/autoconf/spec.gmk.in	Tue Feb 12 14:23:49 2019 +0100
+++ b/make/autoconf/spec.gmk.in	Tue Feb 12 15:31:40 2019 +0100
@@ -36,6 +36,9 @@
 # A self-referential reference to this file.
 SPEC:=@SPEC@
 
+# Path to autoconf if overriden by the user, to be used by "make reconfigure"
+AUTOCONF := @AUTOCONF@
+
 # SPACE and COMMA are defined in MakeBase.gmk, but they are also used in
 # some definitions here, and are needed if MakeBase.gmk is not included before
 # this file.