diff --git a/config/ChangeLog b/config/ChangeLog
index 32c912682a..92df0eb25a 100644
--- a/config/ChangeLog
+++ b/config/ChangeLog
@@ -1,3 +1,9 @@
+2008-05-12  Samuel Tardieu  <sam@rfc1149.net>
+	    Paolo Bonzini  <bonzini@gnu.org>
+
+	PR ada/36001
+	* acx.m4: Add optional parameter to ACX_PROG_GNAT.
+
 2008-04-23  Paolo Bonzini  <bonzini@gnu.org>
 
 	* override.m4: Apply _AC_ARG_VALIDATE fix to all versions
diff --git a/config/acx.m4 b/config/acx.m4
index d186a4cccc..cea08b7204 100644
--- a/config/acx.m4
+++ b/config/acx.m4
@@ -357,7 +357,8 @@ ac_c_preproc_warn_flag=yes])# AC_PROG_CPP_WERROR
 
 # Test for GNAT.
 # We require the gnatbind program, and a compiler driver that
-# understands Ada.  We use the user's CC setting, already found.
+# understands Ada.  We use the user's CC setting, already found,
+# and possibly add $1 to the command-line parameters.
 #
 # Sets the shell variable have_gnat to yes or no as appropriate, and
 # substitutes GNATBIND and GNATMAKE.
@@ -380,7 +381,7 @@ acx_cv_cc_gcc_supports_ada=no
 # Other compilers, like HP Tru64 UNIX cc, exit successfully when
 # given a .adb file, but produce no object file.  So we must check
 # if an object file was really produced to guard against this.
-errors=`(${CC} -c conftest.adb) 2>&1 || echo failure`
+errors=`(${CC} $1[]m4_ifval([$1], [ ])-c conftest.adb) 2>&1 || echo failure`
 if test x"$errors" = x && test -f conftest.$ac_objext; then
   acx_cv_cc_gcc_supports_ada=yes
 fi