--- flex-2.6.1.orig/src/Makefile.am	2016-02-27 14:53:59.000000000 +0100
+++ flex-2.6.1/src/Makefile.am	2016-06-20 23:42:55.000000000 +0200
@@ -90,7 +90,7 @@ stage1scan.l: scan.l
 	cp $(srcdir)/scan.l $(srcdir)/stage1scan.l
 
 stage1scan.c: stage1scan.l stage1flex$(EXEEXT)
-	$(top_builddir)/src/stage1flex$(EXEEXT) -o $@ $<
+	$(STAGE1FLEX) -o $@ $<
 
 # Explicitly describe dependencies.
 # You can recreate this with `gcc -I. -MM *.c'