diff --git a/src/eval.c b/src/eval.c
index b6bee5a..0d15a70 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -3772,7 +3772,14 @@
 	    s = partial_name(pt);
 	}
 	else
+	{
 	    s = functv.vval.v_string;
+	    if (s == NULL || *s == NUL)
+	    {
+		emsg(_(e_empty_function_name));
+		goto theend;
+	    }
+	}
     }
     else
 	s = (char_u *)"";
@@ -3786,6 +3793,7 @@
     funcexe.basetv = basetv;
     ret = get_func_tv(s, -1, rettv, arg, evalarg, &funcexe);
 
+theend:
     // Clear the funcref afterwards, so that deleting it while
     // evaluating the arguments is possible (see test55).
     if (evaluate)