diff --git a/src/eval.c b/src/eval.c
index 61b09fb..e2980a2 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -5314,7 +5314,8 @@
 
 		if (echo_style)
 		{
-		    r = make_ufunc_name_readable(tv->vval.v_string,
+		    r = tv->vval.v_string == NULL ? (char_u *)"function()"
+				  : make_ufunc_name_readable(tv->vval.v_string,
 						       buf, MAX_FUNC_NAME_LEN);
 		    if (r == buf)
 		    {