diff --git a/fox32rom.def b/fox32rom.def
index 0217333..17998d7 100644
--- a/fox32rom.def
+++ b/fox32rom.def
@@ -111,6 +111,7 @@ const EVENT_TYPE_MENU_ACK:       0x00000007
 const EVENT_TYPE_EMPTY:          0xFFFFFFFF
 
 ; keys
+const KEY_CTRL:   0x1D
 const KEY_LSHIFT: 0x2A
 const KEY_RSHIFT: 0x36
 const KEY_CAPS:   0x3A
diff --git a/monitor/keyboard.asm b/monitor/keyboard.asm
index ed9677f..b25b75b 100644
--- a/monitor/keyboard.asm
+++ b/monitor/keyboard.asm
@@ -53,6 +53,7 @@ caps_pressed:
 
 ; scancode set 1:
 ; https://wiki.osdev.org/PS/2_Keyboard#Scan_Code_Set_1
+const CTRL:   0x1D
 const LSHIFT: 0x2A
 const RSHIFT: 0x36
 const CAPS:   0x3A