diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 2e86296..cdf5aa1 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -109,7 +109,7 @@
 	hose = pci_bus_to_host(bus);
 
 	/* Check if we have IOs allocated */
-	if (hose->io_base_alloc == 0)
+	if (hose->io_base_alloc == NULL)
 		return 0;
 
 	pr_debug("IO unmapping for PHB %s\n", hose->dn->full_name);