diff --git a/src/testdir/test_vim9_class.vim b/src/testdir/test_vim9_class.vim
index bc8a8e1..4b6a730 100644
--- a/src/testdir/test_vim9_class.vim
+++ b/src/testdir/test_vim9_class.vim
@@ -203,6 +203,13 @@
   v9.CheckScriptSuccess(lines)
 enddef
 
+def Test_using_null_class()
+  var lines =<< trim END
+      @_ = null_class.member
+  END
+  v9.CheckDefExecAndScriptFailure(lines, ['E715:', 'E1363:'])
+enddef
+
 def Test_class_interface_wrong_end()
   var lines =<< trim END
       vim9script
diff --git a/src/version.c b/src/version.c
index 0265c47..2dca10d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1402,
+/**/
     1401,
 /**/
     1400,
diff --git a/src/vim9class.c b/src/vim9class.c
index 74664f1..8174351 100644
--- a/src/vim9class.c
+++ b/src/vim9class.c
@@ -1262,6 +1262,12 @@
 	cl = rettv->vval.v_object->obj_class;
     }
 
+    if (cl == NULL)
+    {
+	emsg(_(e_incomplete_type));
+	return FAIL;
+    }
+
     if (*name_end == '(')
     {
 	int on_class = rettv->v_type == VAR_CLASS;