diff --git a/m4/Makefile.in b/m4/Makefile.in
index 7b1407c61..6b5569e02 100644
--- a/m4/Makefile.in
+++ b/m4/Makefile.in
@@ -70,7 +70,6 @@ CXX = @CXX@
 CXXCPP = @CXXCPP@
 DATADIRNAME = @DATADIRNAME@
 DEPDIR = @DEPDIR@
-DF_PROG = @DF_PROG@
 GENCAT = @GENCAT@
 GETCONF = @GETCONF@
 GMOFILES = @GMOFILES@
@@ -91,6 +90,7 @@ PACKAGE = @PACKAGE@
 PERL = @PERL@
 POFILES = @POFILES@
 POSUB = @POSUB@
+POW_LIBM = @POW_LIBM@
 RANLIB = @RANLIB@
 U = @U@
 USE_INCLUDED_LIBINTL = @USE_INCLUDED_LIBINTL@
diff --git a/tests/tail-2/Makefile.in b/tests/tail-2/Makefile.in
index 5e8582520..40d349a57 100644
--- a/tests/tail-2/Makefile.in
+++ b/tests/tail-2/Makefile.in
@@ -111,7 +111,7 @@ TESTS_ENVIRONMENT = \
   PROG=tail
 
 
-TESTS = assert
+TESTS = assert fflush
 subdir = tests/tail-2
 mkinstalldirs = $(SHELL) $(top_srcdir)/mkinstalldirs
 CONFIG_HEADER = ../../config.h