diff --git a/src/testing.c b/src/testing.c
index ac9beea..3ab9dcd 100644
--- a/src/testing.c
+++ b/src/testing.c
@@ -758,9 +758,10 @@
     switch (argvars[0].v_type)
     {
 	case VAR_UNKNOWN:
+	case VAR_VOID:
 	case VAR_NUMBER:
-	case VAR_FLOAT:
 	case VAR_BOOL:
+	case VAR_FLOAT:
 	case VAR_SPECIAL:
 	case VAR_STRING:
 	    break;
@@ -781,7 +782,7 @@
 	    {
 		ufunc_T *fp;
 
-		fp = find_func(argvars[0].vval.v_string);
+		fp = find_func(argvars[0].vval.v_string, NULL);
 		if (fp != NULL)
 		    retval = fp->uf_refcount;
 	    }