m4_define([TEST_CONFIGURE], [AT_KEYWORDS([configure])dnl
AT_CHECK([export CC
-CONFIG_SHELL=$TEST_SHELL $TEST_SHELL ./configure --quiet CONFIG_SHELL=$TEST_SHELL $1])])
+CONFIG_SHELL=$TEST_SHELL $TEST_SHELL m4_default([$2],
+[./configure]) --quiet CONFIG_SHELL=$TEST_SHELL $1])])
m4_include([tests/macros.at])
m4_include([tests/snippets.at])