diff --git a/tests/atlocal.in b/tests/atlocal.in
index 471a2980..1a2e4613 100644
--- a/tests/atlocal.in
+++ b/tests/atlocal.in
@@ -16,9 +16,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# We need 'testsuite.h' (srcdir/test), 'config.h' (builddir/lib), and
-# the gnulib headers (srcdir/lib).
-CPPFLAGS="-I$abs_top_srcdir/tests -I$abs_top_srcdir/lib -I$abs_top_builddir/lib @CPPFLAGS@"
+# We need 'testsuite.h' (srcdir/test).
+CPPFLAGS="-I$abs_top_srcdir/tests @CPPFLAGS@"
 
 # Don't just check if $POSIXLY_CORRECT is set, as Bash, when launched
 # as /bin/sh, sets the shell variable POSIXLY_CORRECT to y, but not
@@ -73,11 +72,7 @@ fi
 if $BISON_CXX_WORKS; then
   # See AT_DATA_SOURCE_PROLOGUE.
   cat >conftest.cc <<EOF
-#include <config.h>
-/* We don't need perfect functions for these tests. */
-#undef malloc
-#undef memcmp
-#undef realloc
+#include <testsuite.h>
 #include <iostream>
 
 int main ()
diff --git a/tests/input.at b/tests/input.at
index 976e5395..e77ae90c 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -1322,7 +1322,7 @@ yylex (void)
   */
   enum { input_elts = sizeof input };
   (void) input_elts;
-  static ptrdiff_t toknum;
+  static int toknum;
   assert (0 <= toknum && toknum < input_elts);
   yylval = value_as_yystype (input[toknum]);
   return input[toknum++];
diff --git a/tests/local.at b/tests/local.at
index d8811b0e..24899352 100644
--- a/tests/local.at
+++ b/tests/local.at
@@ -388,7 +388,7 @@ m4_define([AT_LANG_DISPATCH],
 # The prologue that should be included in any source code that is
 # meant to be compiled.  Keep atlocal.in sync (BISON_CXX_WORKS).
 m4_define([AT_DATA_SOURCE_PROLOGUE],
-[[/* Load config.h, and adjust to the compiler.
+[[/* Adjust to the compiler.
   We used to do it here, but each time we add a new line,
   we have to adjust all the line numbers in error messages.
   It's simpler to use a constant include to a varying file.  */
diff --git a/tests/testsuite.h b/tests/testsuite.h
index e4c8298d..3a2a3626 100644
--- a/tests/testsuite.h
+++ b/tests/testsuite.h
@@ -1,4 +1,3 @@
-#include <config.h>
 /* We don't need perfect functions for these tests. */
 #undef malloc
 #undef memcmp