diff --git a/programs/hello/src/main.cpp b/programs/hello/src/main.cpp
index 648ce257..8b2f06a8 100644
--- a/programs/hello/src/main.cpp
+++ b/programs/hello/src/main.cpp
@@ -16,7 +16,7 @@ uint8_t make_color(uint8_t fg, uint8_t bg){
     return fg | bg << 4;
 }
 
-uint16_t make_vga_entry(char c, uint8_t color){
+uint16_t make_vga_entry(const char c, uint8_t color){
     uint16_t c16 = c;
     uint16_t color16 = color;
     return c16 | color16 << 8;