diff --git a/src/northbridge/intel/gm45/northbridge.c b/src/northbridge/intel/gm45/northbridge.c
index cd64dfe..b3dbe16 100644
--- a/src/northbridge/intel/gm45/northbridge.c
+++ b/src/northbridge/intel/gm45/northbridge.c
@@ -178,14 +178,10 @@
 
 static void mch_domain_init(struct device *dev)
 {
-	u32 reg32;
-
 	struct device *mch = pcidev_on_root(0, 0);
 
 	/* Enable SERR */
-	reg32 = pci_read_config32(mch, PCI_COMMAND);
-	reg32 |= PCI_COMMAND_SERR;
-	pci_write_config32(mch, PCI_COMMAND, reg32);
+	pci_or_config16(mch, PCI_COMMAND, PCI_COMMAND_SERR);
 }
 
 static const char *northbridge_acpi_name(const struct device *dev)