Create a tests subdirectory and move one of the test to there.
diff --git a/configure.in b/configure.in
index 49b3195..b2c3cbe 100644
--- a/configure.in
+++ b/configure.in
@@ -5,6 +5,8 @@
 
 AM_INIT_AUTOMAKE(AC_PACKAGE_NAME, AC_PACKAGE_VERSION)
 
+AC_PROG_MAKE_SET
+
 # Checks for programs.
 
 # Checks for libraries.
@@ -29,7 +31,11 @@
 
 AM_PROG_LIBTOOL
 
-AC_OUTPUT([
+AC_CONFIG_FILES([
 Makefile
 json.pc
+tests/Makefile
 ])
+
+AC_OUTPUT
+