diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index b0cc47c..e8e8973 100644
--- a/drivers/tty/rocket.c
+++ b/drivers/tty/rocket.c
@@ -1913,7 +1913,7 @@
 	ByteIO_t UPCIRingInd = 0;
 
 	if (!dev || !pci_match_id(rocket_pci_ids, dev) ||
-	    pci_enable_device(dev))
+	    pci_enable_device(dev) || i >= NUM_BOARDS)
 		return 0;
 
 	rcktpt_io_addr[i] = pci_resource_start(dev, 0);