diff --git a/arch/powerpc/platforms/maple/pci.c b/arch/powerpc/platforms/maple/pci.c
index dc05af5156a9911372822b025ac71dd098ca0e9d..ec5c14f5ba491777cb4d3a782c7fc35b7e4586a9 100644
--- a/arch/powerpc/platforms/maple/pci.c
+++ b/arch/powerpc/platforms/maple/pci.c
@@ -213,6 +213,9 @@ static int u3_ht_read_config(struct pci_bus *bus, unsigned int devfn,
 	if (hose == NULL)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
+	if (offset > 0xff)
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
 	addr = u3_ht_cfg_access(hose, bus->number, devfn, offset);
 	if (!addr)
 		return PCIBIOS_DEVICE_NOT_FOUND;
@@ -245,6 +248,9 @@ static int u3_ht_write_config(struct pci_bus *bus, unsigned int devfn,
 	if (hose == NULL)
 		return PCIBIOS_DEVICE_NOT_FOUND;
 
+	if (offset > 0xff)
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
 	addr = u3_ht_cfg_access(hose, bus->number, devfn, offset);
 	if (!addr)
 		return PCIBIOS_DEVICE_NOT_FOUND;