diff --git a/vala/undef_ref/a.vala b/vala/undef_ref/a.vala
new file mode 100644
index 0000000..be25e3c
--- /dev/null
+++ b/vala/undef_ref/a.vala
@@ -0,0 +1,4 @@
+static void main () {
+  stdout.printf ("Hello world!\n");
+  func ();
+}
diff --git a/vala/undef_ref/b.h b/vala/undef_ref/b.h
new file mode 100644
index 0000000..1cddcbd
--- /dev/null
+++ b/vala/undef_ref/b.h
@@ -0,0 +1 @@
+void func (void) G_GNUC_CONST;
diff --git a/vala/undef_ref/b.vapi b/vala/undef_ref/b.vapi
new file mode 100644
index 0000000..b6cf20e
--- /dev/null
+++ b/vala/undef_ref/b.vapi
@@ -0,0 +1 @@
+void func ();
diff --git a/vala/undef_ref/test_lin.sh b/vala/undef_ref/test_lin.sh
new file mode 100755
index 0000000..8667d1a
--- /dev/null
+++ b/vala/undef_ref/test_lin.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+# in one step
+#valac -C a.vala --vapidir=. --pkg=b -X -fPIC && gcc -fPIC -shared -o libaaa.so a.vala.o -lm
+
+valac -C a.vala --vapidir=. --pkg=b -X -fPIC
+gcc `pkg-config --cflags glib-2.0` -fPIC -shared -o libaaa.so a.c -lm `pkg-config --libs glib-2.0`
diff --git a/vala/undef_ref/test_win.sh b/vala/undef_ref/test_win.sh
new file mode 100755
index 0000000..9298fb0
--- /dev/null
+++ b/vala/undef_ref/test_win.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+# ???