diff --git a/drivers/pci/pci-stub.c b/drivers/pci/pci-stub.c
index f7b68ca6cc98301d0d4d13bdc43d7af8be6f1ab4..4c0336b31cafb5fa3b0c00d51b9f7ab03bbb5c8c 100644
--- a/drivers/pci/pci-stub.c
+++ b/drivers/pci/pci-stub.c
@@ -47,6 +47,10 @@ static int __init pci_stub_init(void)
 	if (rc)
 		return rc;
 
+	/* no ids passed actually */
+	if (ids[0] == '\0')
+		return 0;
+
 	/* add ids specified in the module parameter */
 	p = ids;
 	while ((id = strsep(&p, ","))) {