diff --git a/tests/atlocal.in b/tests/atlocal.in
index a67c4dc..9f6a8ad 100644
--- a/tests/atlocal.in
+++ b/tests/atlocal.in
@@ -10,8 +10,8 @@ CC='@CC@'
 # We want no optimization.
 CFLAGS='@O0CFLAGS@ @WARN_CFLAGS@ @WERROR_CFLAGS@'
 
-# We need `config.h'.
-CPPFLAGS="-I$abs_top_builddir/lib @CPPFLAGS@"
+# We need alarm() from <unistd.h>.
+CPPFLAGS='@CPPFLAGS@ address@hidden@'
 
 # Is the compiler GCC?
 GCC='@GCC@'
diff --git a/tests/local.at b/tests/local.at
index 3b4f03b..21a140b 100644
--- a/tests/local.at
+++ b/tests/local.at
@@ -150,7 +150,7 @@ m4_popdef([AT_LALR1_CC_IF])
 # meant to be compiled.
 m4_define([AT_DATA_GRAMMAR_PROLOGUE],
 [[%{
-#include <config.h>
+/* #include <config.h> */
 /* We don't need perfect functions for these tests. */
 #undef malloc
 #undef memcmp