diff --git a/config/acx.m4 b/config/acx.m4
index b86c4f9..bd3e7f8 100644
--- a/config/acx.m4
+++ b/config/acx.m4
@@ -396,6 +396,10 @@ AC_CHECK_TOOL(GNATMAKE, gnatmake, no)
 AC_CACHE_CHECK([whether compiler driver understands Ada],
 		 acx_cv_cc_gcc_supports_ada,
 [cat >conftest.adb <<EOF
+pragma Warnings (Off);
+with System.CRTL;
+pragma Warnings (On);
+use type System.CRTL.int64;
 procedure conftest is begin null; end conftest;
 EOF
 acx_cv_cc_gcc_supports_ada=no
diff --git a/configure b/configure
index 65d7078..3ddcc9f 100755
--- a/configure
+++ b/configure
@@ -5608,6 +5608,10 @@ if ${acx_cv_cc_gcc_supports_ada+:} false; then :
   $as_echo_n "(cached) " >&6
 else
   cat >conftest.adb <<EOF
+pragma Warnings (Off);
+with System.CRTL;
+pragma Warnings (On);
+use type System.CRTL.int64;
 procedure conftest is begin null; end conftest;
 EOF
 acx_cv_cc_gcc_supports_ada=no