diff --git a/src/mainboard/foxconn/d41s/romstage.c b/src/mainboard/foxconn/d41s/romstage.c
index ecff4b9a2d..cdd12dc3ac 100644
--- a/src/mainboard/foxconn/d41s/romstage.c
+++ b/src/mainboard/foxconn/d41s/romstage.c
@@ -28,8 +28,7 @@ void mb_enable_lpc(void)
 	/* Disable Serial IRQ */
 	pci_write_config8(PCI_DEV(0, 0x1f, 0), SERIRQ_CNTL, 0xd0);
 	/* Decode range */
-	pci_write_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC,
-		pci_read_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC) | 0x0010);
+	pci_or_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC, 0x0010);
 	pci_write_config16(PCI_DEV(0, 0x1f, 0), LPC_EN, CNF1_LPC_EN | KBC_LPC_EN
 			   | FDD_LPC_EN | LPT_LPC_EN | COMB_LPC_EN
 			   | COMA_LPC_EN);
diff --git a/src/mainboard/intel/d510mo/romstage.c b/src/mainboard/intel/d510mo/romstage.c
index c91d40e890..024c3e10fe 100644
--- a/src/mainboard/intel/d510mo/romstage.c
+++ b/src/mainboard/intel/d510mo/romstage.c
@@ -28,8 +28,7 @@ void mb_enable_lpc(void)
 	/* Disable Serial IRQ */
 	pci_write_config8(PCI_DEV(0, 0x1f, 0), SERIRQ_CNTL, 0x00);
 	/* Decode range */
-	pci_write_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC,
-		pci_read_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC) | 0x0010);
+	pci_or_config16(PCI_DEV(0, 0x1f, 0), LPC_IO_DEC, 0x0010);
 	pci_write_config16(PCI_DEV(0, 0x1f, 0), LPC_EN, CNF1_LPC_EN
 			| CNF2_LPC_EN | KBC_LPC_EN | COMA_LPC_EN
 			| COMB_LPC_EN);