diff --git a/tools/intel_vga_read.c b/tools/intel_vga_read.c
index e635c59c..ea507057 100644
--- a/tools/intel_vga_read.c
+++ b/tools/intel_vga_read.c
@@ -37,7 +37,7 @@
 static uint8_t read_reg(uint32_t reg, bool use_mmio)
 {
 	if (use_mmio)
-		return *((volatile uint8_t *)mmio + reg);
+		return INREG8(reg);
 	else
 		return inb(reg);
 }
diff --git a/tools/intel_vga_write.c b/tools/intel_vga_write.c
index 4fb09d6a..82159624 100644
--- a/tools/intel_vga_write.c
+++ b/tools/intel_vga_write.c
@@ -37,7 +37,7 @@
 static void write_reg(uint32_t reg, uint8_t val, bool use_mmio)
 {
 	if (use_mmio)
-		*((volatile uint8_t *)mmio + reg) = val;
+		OUTREG8(reg, val);
 	else
 		outb(val, reg);
 }