diff --git a/arch/cga.cc b/arch/cga.cc
index 345ee5b..f113ef6 100644
--- a/arch/cga.cc
+++ b/arch/cga.cc
@@ -9,7 +9,7 @@ namespace CGA {
 
   void writeCGAReg(int reg, int data){
     index_port.outb(reg);
-    data_port.outw(data);
+    data_port.outb(data);
   }
 
   uint16_t readCGAReg(int reg){