diff --git a/arch/powerpc/platforms/iseries/pci.c b/arch/powerpc/platforms/iseries/pci.c
index 3fc2e6494b8b..ab3962b0d246 100644
--- a/arch/powerpc/platforms/iseries/pci.c
+++ b/arch/powerpc/platforms/iseries/pci.c
@@ -445,7 +445,11 @@ void __init iSeries_pcibios_fixup_resources(struct pci_dev *pdev)
 	}
 
 	allocate_device_bars(pdev);
-	iseries_device_information(pdev, bus, *sub_bus);
+	if (likely(sub_bus))
+		iseries_device_information(pdev, bus, *sub_bus);
+	else
+		printk(KERN_ERR "PCI: Device node %s has missing or invalid "
+				"linux,subbus property\n", node->full_name);
 }
 
 /*